{"id":55573,"date":"2021-08-20T20:27:00","date_gmt":"2021-08-20T14:57:00","guid":{"rendered":"https:\/\/www.kopykitab.com\/blog\/?p=55573"},"modified":"2021-08-28T12:48:40","modified_gmt":"2021-08-28T07:18:40","slug":"ncert-solutions-for-class-11-chemistry-chapter-3","status":"publish","type":"post","link":"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/","title":{"rendered":"Class 11 Chemistry Chapter 3 NCERT Solutions 2021 For Classification of Elements and Periodicity in Properties"},"content":{"rendered":"\n<p>\u00a0<\/p>\n<p><img class=\"alignnone size-full wp-image-109903\" src=\"https:\/\/www.kopykitab.com\/blog\/wp-content\/uploads\/2021\/07\/NCERT-Solutions-For-Class-11-Chemistry-Chapter-3-Classification-of-Elements-and-Periodicity-in-Properties.jpg\" alt=\"NCERT Solutions For Class 11 Chemistry Chapter 3\" width=\"1200\" height=\"675\" srcset=\"https:\/\/www.kopykitab.com\/blog\/wp-content\/uploads\/2021\/07\/NCERT-Solutions-For-Class-11-Chemistry-Chapter-3-Classification-of-Elements-and-Periodicity-in-Properties.jpg 1200w, https:\/\/www.kopykitab.com\/blog\/wp-content\/uploads\/2021\/07\/NCERT-Solutions-For-Class-11-Chemistry-Chapter-3-Classification-of-Elements-and-Periodicity-in-Properties-768x432.jpg 768w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/> <strong>NCERT Solutions For Class 11 Chemistry Chapter 3<\/strong>: Getting ready with NCERT Solutions For Class 11 Chemistry Chapter 3 might seem easy at the beginning, however, it is not the case to be precise. Class 10 is just a pond compared to the syllabus prescribed in the 11th standard.<\/p>\n<p>And if you aspire for a promising future then getting ready from NCERT Solutions For Class 11 Chemistry Chapter 3 should remain the ultimate goal.<\/p>\n<p>But choosing the right path might confuse students from time to time. So, here we are presenting you NCERT Solutions For Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties, to begin with, your upcoming exam preparation.<\/p>\n<ul>\n<li><a href=\"https:\/\/www.kopykitab.com\/blog\/cbse-class-11-chemistry-ncert-solutions\/\" target=\"_blank\" rel=\"noopener noreferrer\">NCERT Solutions For 11th Chemistry All Chapters<\/a><\/li>\n<\/ul>\n<p>Chemistry is unquestionably a crucial subject to get ready for a prospective future with science stream. Therefore understanding the topics loaded in the curriculum with ease is our utmost goal.<\/p>\n<p>Therefore we offer you NCERT solutions for class 11 chemistry chapter 3 as robust assistance to study for the upcoming test.<\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_47_1 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"ez-toc-toggle-icon-1\"><label for=\"item-69e7d98a90971\" aria-label=\"Table of Content\"><span style=\"display: flex;align-items: center;width: 35px;height: 30px;justify-content: center;direction:ltr;\"><svg style=\"fill: #000000;color:#000000\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #000000;color:#000000\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/label><input  type=\"checkbox\" id=\"item-69e7d98a90971\"><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 eztoc-visibility-hide-by-default' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#ncert-solutions-for-class-11-chemistry-chapter-3-classification-of-elements-and-periodicity-in-properties\" title=\"NCERT Solutions For Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties\">NCERT Solutions For Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#what-will-you-learn-in-cbse-class-11-chemistry-chapter-3\" title=\"What will you learn in CBSE Class 11 Chemistry Chapter 3?\">What will you learn in CBSE Class 11 Chemistry Chapter 3?<\/a><ul class='ez-toc-list-level-4'><li class='ez-toc-heading-level-4'><ul class='ez-toc-list-level-4'><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#types-of-questions-that-students-get-from-this-chapter-are-listed-down\" title=\"Types of questions that students get from this chapter are listed down-\">Types of questions that students get from this chapter are listed down-<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#subtopics-from-ncert-solutions-for-class-11-chemistry-chapter-3\" title=\"Subtopics From NCERT Solutions For Class 11 Chemistry Chapter 3\">Subtopics From NCERT Solutions For Class 11 Chemistry Chapter 3<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#benefits-of-ncert-solutions-for-class-11-chemistry-chapter-3\" title=\"Benefits of NCERT Solutions For Class 11\u00a0Chemistry Chapter 3\">Benefits of NCERT Solutions For Class 11\u00a0Chemistry Chapter 3<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#access-ncert-solutions-for-class-11-chemistry-chapter-3\" title=\"Access NCERT Solutions For Class 11\u00a0Chemistry Chapter 3\">Access NCERT Solutions For Class 11\u00a0Chemistry Chapter 3<\/a><ul class='ez-toc-list-level-3'><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-1-what-is-the-basic-theme-of-organisation-in-the-periodic-table\" title=\"Question 1. What is the basic theme of organisation in the periodic table?\">Question 1. What is the basic theme of organisation in the periodic table?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-2-which-important-property-did-mendeleev-use-to-classify-the-elements-in-this-periodic-table-and-did-he-stick-to-that\" title=\"Question 2. Which important property did Mendeleev use to classify the elements in this periodic table and did he stick to that?\">Question 2. Which important property did Mendeleev use to classify the elements in this periodic table and did he stick to that?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-3-what-is-the-basic-difference-in-approach-between-mendeleev%e2%80%99s-periodic-law-and-the-modem-periodic-law\" title=\"Question 3. What is the basic difference in approach between Mendeleev\u2019s Periodic Law and the Modem Periodic Law?\">Question 3. What is the basic difference in approach between Mendeleev\u2019s Periodic Law and the Modem Periodic Law?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-4-on-the-basis-of-quantum-numbers-justify-that-the-sixth-period-of-the-periodic-table-should-have-32-elements\" title=\"Question 4. On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements.\">Question 4. On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-5-in-terms-of-period-and-group-where-will-you-locate-the-element-with-z-114\" title=\"Question 5. In terms of period and group where will you locate the element with z = 114?\">Question 5. In terms of period and group where will you locate the element with z = 114?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-6-write-the-atomic-number-of-the-element-present-in-the-third-period-and-seventeenth-group-of-the-periodic-table\" title=\"Question 6. Write the atomic number of the element present in the third period and seventeenth group of the periodic table.\">Question 6. Write the atomic number of the element present in the third period and seventeenth group of the periodic table.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-7-which-element-do-you-think-would-have-been-named-by-ilawrence-berkeley-laboratory-iiseaborg%e2%80%99s-group\" title=\"Question 7. Which element do you think would have been named by (i)Lawrence Berkeley Laboratory (ii)Seaborg\u2019s group?\">Question 7. Which element do you think would have been named by (i)Lawrence Berkeley Laboratory (ii)Seaborg\u2019s group?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-8-why-do-elements-in-the-same-group-have-similar-physical-and-chemical-properties\" title=\"Question 8. Why do elements in the same group have similar physical and chemical properties?\">Question 8. Why do elements in the same group have similar physical and chemical properties?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-9-what-does-atomic-radius-and-ionic-radius-really-mean-to-you\" title=\"Question 9. What does atomic radius and ionic radius really mean to you?\">Question 9. What does atomic radius and ionic radius really mean to you?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-10-how-do-atomic-radius-vary-in-a-period-and-in-a-group-how-do-you-explain-the-variation\" title=\"Question 10. How do atomic radius vary in a period and in a group? How do you explain the variation?\">Question 10. How do atomic radius vary in a period and in a group? How do you explain the variation?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-11-what-do-you-understand-by-isoelectronic-species-name-a-species-that-will-be-iso-electronic-with-each-of-the-following-atoms-or-ions-i-f%e2%80%93ii-ar-iii-mg2iv-rb\" title=\"Question 11. What do you understand by isoelectronic species? Name a species that will be iso electronic with each of the following atoms or ions. (i) F\u2013(ii) Ar (iii) Mg2+(iv)\u00a0Rb+\">Question 11. What do you understand by isoelectronic species? Name a species that will be iso electronic with each of the following atoms or ions. (i) F\u2013(ii) Ar (iii) Mg2+(iv)\u00a0Rb+<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-12-consider-the-following-species-n3-o2-f%e2%80%93-na-mg2-al3-a-what-is-common-in-them-b-arrange-them-in-order-of-increasing-ionic-radii\" title=\"Question 12. Consider the following species: N3-,\u00a0O2-,\u00a0F\u2013, Na+, Mg2+,\u00a0Al3+ (a) What is common in them? (b) Arrange them in order of increasing ionic radii?\">Question 12. Consider the following species: N3-,\u00a0O2-,\u00a0F\u2013, Na+, Mg2+,\u00a0Al3+ (a) What is common in them? (b) Arrange them in order of increasing ionic radii?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-13-explain-why-cation-are-smaller-and-anions-larger-in-radii-than-their-parent-atoms\" title=\"Question 13. Explain why cation are smaller and anions larger in radii than their parent atoms?\">Question 13. Explain why cation are smaller and anions larger in radii than their parent atoms?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-14-what-is-the-significance-of-the-terms-%e2%80%93-isolated-gaseous-atom-and-ground-state-while-defining-the-ionization-enthalpy-and-electron-gain-enthalpyhint-requirements-for-comparison-purposes\" title=\"Question 14. What is the significance of the terms \u2013 isolated gaseous atom and ground state while defining the ionization enthalpy and electron gain enthalpy?[Hint: Requirements for comparison purposes]\">Question 14. What is the significance of the terms \u2013 isolated gaseous atom and ground state while defining the ionization enthalpy and electron gain enthalpy?[Hint: Requirements for comparison purposes]<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-15-energy-of-an-electron-in-the-ground-state-of-the-hydrogen-atom-is-218-x-10-18-calculate-the-ionization-enthalpy-of-atomic-hydrogen-in-terms-of-jmol-1hint-apply-the-idea-of-mole-concept-to-derive-the-answer\" title=\"Question 15. Energy of an electron in the ground state of the hydrogen atom is- 2.18 x 10-18\u00a0Calculate\u00a0the ionization enthalpy of atomic hydrogen in terms of JMol-1.[Hint: Apply the idea of mole concept to derive the answer],\">Question 15. Energy of an electron in the ground state of the hydrogen atom is- 2.18 x 10-18\u00a0Calculate\u00a0the ionization enthalpy of atomic hydrogen in terms of JMol-1.[Hint: Apply the idea of mole concept to derive the answer],<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-16-among-the-second-period-elements-the-actual-ionization-enthalpies-are-in-the-order-li\" title=\"Question 16. Among the second period elements, the actual ionization enthalpies are in the order: Li &lt;B&lt; Be &lt;C&lt;0&lt;KI&lt;F&lt; Ne Explain why (i) Be has higher \u2206iH1than B ? (ii) O has lower \u2206iH1\u00a0than N and F?\">Question 16. Among the second period elements, the actual ionization enthalpies are in the order: Li &lt;B&lt; Be &lt;C&lt;0&lt;KI&lt;F&lt; Ne Explain why (i) Be has higher \u2206iH1than B ? (ii) O has lower \u2206iH1\u00a0than N and F?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-17-how-would-you-explain-the-fact-that-the-first-ionization-enthalpy-of-sodium-is-lower-than-that-of-magnesium-but-its-second-ionization-enthalpy-is-higher-than-that-of-magnesium\" title=\"Question 17. How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?\">Question 17. How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-18-what-are-the-various-factors-due-to-which-the-ionization-enthalpy-of-the-main-group-elements-tends-to-decrease-down-the-group\" title=\"Question 18. What are the various factors due to which the ionization enthalpy of the main group elements tends to decrease down the group?\">Question 18. What are the various factors due to which the ionization enthalpy of the main group elements tends to decrease down the group?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-19-the-first-ionization-enthalpy-values-in-kj-mol-1-of-group-13-elements-are-b-al-ga-in-tl-801-577-579-558-589-how-would-you-explain-this-deviation-from-the-general-trend\" title=\"Question 19. The first ionization enthalpy values (in kJ mol\u00a0-1) of group 13 elements are: B Al Ga In Tl 801 577 579 558 589 How would you explain this deviation from the general trend?\">Question 19. The first ionization enthalpy values (in kJ mol\u00a0-1) of group 13 elements are: B Al Ga In Tl 801 577 579 558 589 How would you explain this deviation from the general trend?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-20-which-of-the-following-pairs-of-elements-would-have-a-move-negative-electron-gain-enthalpy-i-o-or-f-ii-f-or-cl\" title=\"Question 20. Which of the following pairs of elements would have a move negative electron gain enthalpy?\u00a0(i) O or F (ii) F or Cl.\">Question 20. Which of the following pairs of elements would have a move negative electron gain enthalpy?\u00a0(i) O or F (ii) F or Cl.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-21-would-you-expect-the-second-electron-gain-enthalpy-of-o-as-positive-more-negative-or-less-negative-than-the-first-justify-your-answer\" title=\"Question 21. Would you expect the second electron gain enthalpy of O as positive, more negative or less negative than the first? Justify your answer.\">Question 21. Would you expect the second electron gain enthalpy of O as positive, more negative or less negative than the first? Justify your answer.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-28\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-22-what-is-basic-difference-between-the-terms-electron-gain-enthalpy-and-electro-negativity\" title=\"Question 22. What is basic difference between the terms electron gain enthalpy and electro negativity?\">Question 22. What is basic difference between the terms electron gain enthalpy and electro negativity?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-29\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#23-how-would-you-react-to-the-statement-that-the-electronegativity-of-on-pauling-scale-is-30-in-all-the-nitrogen-compounds\" title=\"23. How would you react to the statement that the electronegativity of on Pauling scale is 3.0 in all the nitrogen compounds?\">23. How would you react to the statement that the electronegativity of on Pauling scale is 3.0 in all the nitrogen compounds?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-30\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-24-describe-the-theory-associated-with-the-radius-of-an-atom-as-it-a-gains-an-electron-b-loses-an-electron\" title=\"Question 24. Describe the theory associated with the radius of an atom as it: (a) gains an electron (b) loses an electron ?\">Question 24. Describe the theory associated with the radius of an atom as it: (a) gains an electron (b) loses an electron ?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-31\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-25-would-you-expect-the-first-ionization-enthalpies-of-two-isotopes-of-the-same-element-to-be-the-same-or-different-justify-your-answer\" title=\"Question 25. Would you expect the first ionization enthalpies of two isotopes of the same element to be the same or different? Justify your answer.\">Question 25. Would you expect the first ionization enthalpies of two isotopes of the same element to be the same or different? Justify your answer.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-32\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-26-what-are-major-differences-between-metals-and-non-metals\" title=\"Question 26. What are major differences between metals and non-metals?\">Question 26. What are major differences between metals and non-metals?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-33\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-27-use-periodic-table-to-answer-the-following-questions-a-identify-the-element-with-five-electrons-in-the-outer-subshell-b-identify-the-element-that-would-tend-to-lose-two-electrons-c-identify-the-element-that-would-tend-to-gain-two-electrons\" title=\"Question 27. Use periodic table to answer the following questions: (a) Identify the element with five electrons in the outer subshell. (b) Identify the element that would tend to lose two electrons. (c) Identify the element that would tend to gain two electrons.\">Question 27. Use periodic table to answer the following questions: (a) Identify the element with five electrons in the outer subshell. (b) Identify the element that would tend to lose two electrons. (c) Identify the element that would tend to gain two electrons.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-34\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-28-the-increasing-order-of-reactivity-among-group-1-elements-is-li-%3c-na-%3c-k-%3c-rb-%3c-cs-whereas-that-of-group-17-is-f-%3e-cl-%3e-br-%3e-i-explain\" title=\"Question 28. The increasing order of reactivity among group 1 elements is Li &lt; Na &lt; K &lt; Rb &lt; Cs whereas that of group 17 is F &gt; Cl &gt; Br &gt; I. Explain?\">Question 28. The increasing order of reactivity among group 1 elements is Li &lt; Na &lt; K &lt; Rb &lt; Cs whereas that of group 17 is F &gt; Cl &gt; Br &gt; I. Explain?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-35\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-29-write-the-general-electronic-configuration-of-s%e2%80%93-p%e2%80%93-d%e2%80%93-and-f-block-elements\" title=\"Question 29. Write the general electronic configuration of s\u2013\u00a0p\u2013\u00a0d\u2013, and f-block elements?\">Question 29. Write the general electronic configuration of s\u2013\u00a0p\u2013\u00a0d\u2013, and f-block elements?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-36\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-30-assign-the-position-of-the-element-having-outer-electronic-configuration-i-ns2-np4-for-n-3-ii-n-%e2%80%93-1-d2-ns2-for-n-4-and-iii-n-%e2%80%93-2-f7-n-%e2%80%93-1-d1-ns2-for-n-6-in-the-periodic-table\" title=\"Question 30. Assign the position of the element having outer electronic configuration, (i) ns2\u00a0np4\u00a0for n = 3 (ii) (n \u2013 1) d2\u00a0ns2\u00a0for n = 4 and (iii) (n \u2013 2) f7\u00a0(n \u2013 1) d1\u00a0ns2\u00a0for n = 6 in the periodic table?\">Question 30. Assign the position of the element having outer electronic configuration, (i) ns2\u00a0np4\u00a0for n = 3 (ii) (n \u2013 1) d2\u00a0ns2\u00a0for n = 4 and (iii) (n \u2013 2) f7\u00a0(n \u2013 1) d1\u00a0ns2\u00a0for n = 6 in the periodic table?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-37\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-31-which-of-the-above-elements-is-likely-to-be-a-the-least-reactive-element-b-the-most-reactive-metal-c-the-most-reactive-non-metal-d-the-least-reactive-non-metal-e-the-metal-which-can-form-a-stable-binary-halide-of-the-formula-mx2x-halogen-f-the-metal-which-can-form-a-predominantly-stable-covalent-halide-of-the-formula-mx-x-halogen\" title=\"Question 31.   Which of the above elements is likely to be: (a) the least reactive element (b) the most reactive metal (c) the most reactive non-metal (d) the least reactive non-metal (e) the metal which can form a stable binary halide of the formula MX2(X = halogen) (f) the metal which can form a predominantly stable covalent halide of the formula MX (X = halogen)?\">Question 31.   Which of the above elements is likely to be: (a) the least reactive element (b) the most reactive metal (c) the most reactive non-metal (d) the least reactive non-metal (e) the metal which can form a stable binary halide of the formula MX2(X = halogen) (f) the metal which can form a predominantly stable covalent halide of the formula MX (X = halogen)?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-38\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-32-predict-the-formulas-of-the-stable-binary-compounds-that-would-be-formed-by-the-combination-of-the-following-pairs-of-elements-a-lithium-and-oxygenb-magnesium-and-nitrogen-c-aluminium-and-iodined-silicon-and-oxygen-e-phosphorous-pentafluoride-f-element-71-and-fluorine\" title=\"Question 32. Predict the formulas of the stable binary compounds that would be formed by the combination\u00a0of the following pairs of elements: (a) Lithium and oxygen(b) Magnesium and nitrogen (c) Aluminium and iodine(d) Silicon and oxygen (e) Phosphorous pentafluoride (f) Element 71 and fluorine.\">Question 32. Predict the formulas of the stable binary compounds that would be formed by the combination\u00a0of the following pairs of elements: (a) Lithium and oxygen(b) Magnesium and nitrogen (c) Aluminium and iodine(d) Silicon and oxygen (e) Phosphorous pentafluoride (f) Element 71 and fluorine.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-39\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-33-in-the-modem-periodic-table-the-period-indicates-the-value-of-aatomic-number-b-mass-number-c-principal-quantum-number-d-azimuthal-quantum-number\" title=\"Question 33. In the modem periodic table, the period indicates the value of (a)atomic number (b) mass number (c) principal quantum number (d) azimuthal quantum number?\">Question 33. In the modem periodic table, the period indicates the value of (a)atomic number (b) mass number (c) principal quantum number (d) azimuthal quantum number?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-40\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-34-which-of-the-following-statements-related-to-the-modem-periodic-table-is-incorrect-a-the-p-block-has-six-columns-because-a-maximum-of-6-electrons-can-occupy-all-the-orbitals-in-a-p-subshell\" title=\"Question 34. Which of the following statements related to the modem periodic table is incorrect? (a) The p-block has six columns, because a maximum of 6 electrons can occupy all the orbitals in a p-subshell.\">Question 34. Which of the following statements related to the modem periodic table is incorrect? (a) The p-block has six columns, because a maximum of 6 electrons can occupy all the orbitals in a p-subshell.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-41\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#b-the-d-block-has-8-columns-because-a-maximum-of-8-electrons-can-occupy-all-the-orbitals-in-a-d-subshell\" title=\"(b) The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell.\">(b) The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-42\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#c-each-block-contains-a-number-of-columns-equal-to-the-number-of-electrons-that-can-occupy-that-subshell\" title=\"(c) Each block contains a number of columns equal to the number of electrons that can occupy that subshell.\">(c) Each block contains a number of columns equal to the number of electrons that can occupy that subshell.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-43\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#d-the-block-indicates-value-of-azimuthal-quantum-number-lfor-the-last-subshell-that-received-electrons-in-building-up-the-electronic-configuration\" title=\"(d) The block indicates value of azimuthal quantum number (l)for the last subshell that received electrons in building up the electronic configuration.\">(d) The block indicates value of azimuthal quantum number (l)for the last subshell that received electrons in building up the electronic configuration.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-44\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-35-anything-that-influences-the-valence-electrons-will-affect-the-chemistry-of-the-element-which-one-of-the-following-factors-does-not-affect-the-valence-shell-a-valence-principal-quantum-number-n-b-nuclear-charge-z-c-nuclear-mass-d-number-of-core-electrons\" title=\"Question 35. Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell? (a) Valence principal quantum number (n) (b) Nuclear charge (Z) (c) Nuclear mass (d) Number of core electrons.\">Question 35. Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell? (a) Valence principal quantum number (n) (b) Nuclear charge (Z) (c) Nuclear mass (d) Number of core electrons.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-45\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-36-the-size-of-isoelectronic-species-f%e2%80%93-ne-and-na-is-affected-by-a-nuclear-charge-z-b-valence-principal-quantum-number-n-c-electron-electron-interaction-in-the-outer-orbitals-d-none-of-the-factors-because-their-size-is-the-same\" title=\"Question 36. The size of isoelectronic species-F\u2013, Ne and\u00a0Na+\u00a0is affected by (a) nuclear charge (Z) (b) valence principal quantum number (n) (c) electron-electron interaction in the outer orbitals (d) none of the factors because their size is the same\">Question 36. The size of isoelectronic species-F\u2013, Ne and\u00a0Na+\u00a0is affected by (a) nuclear charge (Z) (b) valence principal quantum number (n) (c) electron-electron interaction in the outer orbitals (d) none of the factors because their size is the same<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-46\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-37-which-of-the-following-statements-is-incorrect-in-relation-to-ionization-enthalpy-aionization-enthalpy-increases-for-each-successive-electron\" title=\"Question 37. Which of the following statements is incorrect in relation to ionization enthalpy? (a)ionization enthalpy increases for each successive electron.\">Question 37. Which of the following statements is incorrect in relation to ionization enthalpy? (a)ionization enthalpy increases for each successive electron.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-47\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#bthe-greatest-increase-in-ionization-enthalpy-is-experienced-on-removal-of-electrons-from-core-noble-gas-configuration\" title=\"(b)The greatest increase in ionization enthalpy is experienced on removal of electrons from core noble gas configuration.\">(b)The greatest increase in ionization enthalpy is experienced on removal of electrons from core noble gas configuration.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-48\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#cend-of-valence-electrons-is-marked-by-a-big-jump-in-ionization-enthalpy\" title=\"(c)End of valence electrons is marked by a big jump in ionization enthalpy.\">(c)End of valence electrons is marked by a big jump in ionization enthalpy.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-49\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#dremoval-of-electron-from-orbitals-bearing-lower-n-value-is-easier-than-from-orbital-having-higher-n-value\" title=\"(d)Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.\">(d)Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-50\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-38-considering-the-elements-b-al-mg-and-k-the-correct-order-of-their-metallic-character-is-a-b%3e-al%3e-mg-%3e-kb-al%3e-mg-%3e-b%3e-k-c-mg-%3e-al%3e-k%3e-b-d-k%3e-mg-%3e-al%3e-b\" title=\"Question 38. Considering the elements B, Al, Mg and K, the correct order of their metallic character is:(a) B&gt; Al&gt; Mg &gt; K(b) Al&gt; Mg &gt; B&gt; K (c) Mg &gt; Al&gt; K&gt; B (d) K&gt; Mg &gt; Al&gt; B\">Question 38. Considering the elements B, Al, Mg and K, the correct order of their metallic character is:(a) B&gt; Al&gt; Mg &gt; K(b) Al&gt; Mg &gt; B&gt; K (c) Mg &gt; Al&gt; K&gt; B (d) K&gt; Mg &gt; Al&gt; B<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-51\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-39-considering-the-elements-b-c-n-f-and-si-the-correct-order-of-their-non-metallic-character-is-a-b%3ec%3esi%3en%3ef-b-si%3ec%3eb%3en%3ef-c-f%3en%3ec%3eb%3esi-d-f%3en%3ec%3esi%3eb\" title=\"Question 39. Considering the elements B, C, N, F and Si, the correct order of their non-metallic character is: (a) B&gt;C&gt;Si&gt;N&gt;F (b) Si&gt;C&gt;B&gt;N&gt;F (c) F&gt;N&gt;C&gt;B&gt;Si (d) F&gt;N&gt;C&gt;Si&gt;B\">Question 39. Considering the elements B, C, N, F and Si, the correct order of their non-metallic character is: (a) B&gt;C&gt;Si&gt;N&gt;F (b) Si&gt;C&gt;B&gt;N&gt;F (c) F&gt;N&gt;C&gt;B&gt;Si (d) F&gt;N&gt;C&gt;Si&gt;B<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-52\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-40-considering-the-elements-f-cl-o-and-n-the-correct-order-of-their-chemical-reactivity-in-terms-of-oxidising-property-is-a-f-%3e-cl%3e-o-%3e-n-b-f-%3e-o-%3e-cl%3e-n-c-cl%3e-f-%3e-o-%3e-n-d-o-%3e-f-%3e-n-%3e-cl\" title=\"Question 40. Considering the elements F, Cl, O and N, the correct order of their chemical reactivity in terms of oxidising property is: (a) F &gt; Cl&gt; O &gt; N (b) F &gt; O &gt; Cl&gt; N (c) Cl&gt; F &gt; O &gt; N (d) O &gt; F &gt; N &gt; Cl\">Question 40. Considering the elements F, Cl, O and N, the correct order of their chemical reactivity in terms of oxidising property is: (a) F &gt; Cl&gt; O &gt; N (b) F &gt; O &gt; Cl&gt; N (c) Cl&gt; F &gt; O &gt; N (d) O &gt; F &gt; N &gt; Cl<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-53\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#more-questions-solved\" title=\"MORE QUESTIONS SOLVED\">MORE QUESTIONS SOLVED<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-54\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-1-state-the-modem-periodic-law\" title=\"Question 1. State the Modem Periodic Law.\">Question 1. State the Modem Periodic Law.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-55\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-2-why-is-ionization-enthalpy-of-nitrogen-greater-than-that-of-oxygen\" title=\"Question 2. Why is ionization enthalpy of nitrogen greater than that of oxygen?\">Question 2. Why is ionization enthalpy of nitrogen greater than that of oxygen?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-56\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-3-why-are-electron-gain-enthalpies-of-be-and-mg-positive\" title=\"Question 3. Why are electron gain enthalpies of Be and Mg positive?\">Question 3. Why are electron gain enthalpies of Be and Mg positive?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-57\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-4-give-four-examples-of-species-which-are-isoelectronic-with-ca2\" title=\"Question 4. Give four examples of species which are isoelectronic with\u00a0ca2+.\">Question 4. Give four examples of species which are isoelectronic with\u00a0ca2+.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-58\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-5-which-two-elements-of-the-following-belong-to-the-same-period-al-si-ba-and-o\" title=\"Question 5. Which two elements of the following belong to the same period? Al, Si, Ba and O\">Question 5. Which two elements of the following belong to the same period? Al, Si, Ba and O<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-59\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-6-explain-why-chlorine-can-be-converted-into-chloride-ion-more-easily-as-compared-to-fluoride-ion-from-fluorine\" title=\"Question 6. Explain why chlorine can be converted into chloride ion more easily as compared to fluoride ion from fluorine ?\">Question 6. Explain why chlorine can be converted into chloride ion more easily as compared to fluoride ion from fluorine ?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-60\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-7-what-are-horizontal-rows-and-vertical-columns-of-the-periodic-table-called\" title=\"Question 7. What are horizontal rows and vertical columns of the periodic table called?\">Question 7. What are horizontal rows and vertical columns of the periodic table called?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-61\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-8-which-has-a-larger-radius-img-or-ca-ii-s-or-cl\" title=\"Question 8. Which has a larger radius? (i)Mg or Ca (ii) S or Cl\">Question 8. Which has a larger radius? (i)Mg or Ca (ii) S or Cl<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-62\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-9-what-are-representative-elements\" title=\"Question 9. What are representative elements?\">Question 9. What are representative elements?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-63\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-10-give-general-electronic-configuration-off-block-elements\" title=\"Question 10. Give general electronic configuration off-block elements?\">Question 10. Give general electronic configuration off-block elements?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-64\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-11-what-are-inner-transition-metals-why-are-they-called-rare-earth-metals\" title=\"Question 11. What are inner transition metals? Why are they called rare earth metals?\">Question 11. What are inner transition metals? Why are they called rare earth metals?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-65\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-12-define-ionisation-enthalpy\" title=\"Question 12. Define ionisation enthalpy.\">Question 12. Define ionisation enthalpy.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-66\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-13-the-electronic-configuration-of-an-element-is-is-2s-2p-3s-3p-4s-locate-the-element-in-the-periodic-table\" title=\"Question 13. The electronic configuration of an element is Is 2s 2p 3s 3p 4s . Locate the element in the periodic table.\">Question 13. The electronic configuration of an element is Is 2s 2p 3s 3p 4s . Locate the element in the periodic table.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-67\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-1-what-is-the-cause-of-periodicity-in-properties-of-the-elements-explain-with-two-examples\" title=\"Question 1. What is the cause of periodicity in properties of the elements? Explain with two examples.\">Question 1. What is the cause of periodicity in properties of the elements? Explain with two examples.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-68\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-2-show-by-a-chemical-reaction-with-water-that-na20-is-a-basic-oxide-and-cl207-is-an-acidic-oxide\" title=\"Question 2. Show by a chemical reaction with water that Na20 is a basic oxide and\u00a0Cl207\u00a0is an acidic oxide.\">Question 2. Show by a chemical reaction with water that Na20 is a basic oxide and\u00a0Cl207\u00a0is an acidic oxide.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-69\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-3-what-do-you-understand-by-%e2%80%98representative-elements%e2%80%99-name-the-groups-whose-elements-are-called-representative-elements\" title=\"Question 3. What do you understand by \u2018Representative elements\u2019? Name the groups whose elements are called representative elements.\">Question 3. What do you understand by \u2018Representative elements\u2019? Name the groups whose elements are called representative elements.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-70\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-4-name-different-blocks-of-elements-in-the-periodic-table-give-general-electronic-configuration-of-each-block\" title=\"Question 4. Name different blocks of elements in the periodic table. Give general electronic configuration of each block.\">Question 4. Name different blocks of elements in the periodic table. Give general electronic configuration of each block.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-71\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-5-elements-a-b-c-and-d-iwoe-atomic-numbers-1219-29-and-36-respectively-on-the-basis-of-electronic-configuration-write-to-which-group-of-the-periodic-table-each-element-belongs\" title=\"Question 5. Elements A, B, C and D Iwoe atomic numbers 12,19, 29, and 36 respectively. On the basis of\u00a0electronic configuration, write to which group of the periodic table each element belongs.\">Question 5. Elements A, B, C and D Iwoe atomic numbers 12,19, 29, and 36 respectively. On the basis of\u00a0electronic configuration, write to which group of the periodic table each element belongs.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-72\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-6-define-the-term-ionization-enthalpy-how-does-it-vary-along-a-period-and-along-a-group\" title=\"Question 6. Define the term ionization enthalpy? How does it vary along a period and along a group?\">Question 6. Define the term ionization enthalpy? How does it vary along a period and along a group?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-73\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-7-discuss-briefly-the-various-factors-on-which-ionization-enthalpy-depends\" title=\"Question 7. Discuss briefly the various factors on which ionization enthalpy depends.\">Question 7. Discuss briefly the various factors on which ionization enthalpy depends.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-74\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-8-what-are-dobereiner-triads-name-two-such-triads\" title=\"Question 8. What are Dobereiner triads? Name two such triads.\">Question 8. What are Dobereiner triads? Name two such triads.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-75\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-9-give-the-electronic-configuration-of-the-transition-elements-write-their-four-important-characteristics\" title=\"Question 9. Give the electronic configuration of the transition elements. Write their four important characteristics.\">Question 9. Give the electronic configuration of the transition elements. Write their four important characteristics.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-76\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-10-what-is-screening-or-shielding-effect-how-does-it-influence-the-ionization-enthalpy\" title=\"Question 10. What is screening or shielding effect? How does it influence the ionization enthalpy ?\">Question 10. What is screening or shielding effect? How does it influence the ionization enthalpy ?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-77\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-11-define-electron-gain-enthalpy-what-are-its-units\" title=\"Question 11. Define electron gain enthalpy. What are its units?\">Question 11. Define electron gain enthalpy. What are its units?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-78\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-1-discuss-the-main-features-of-long-form-of-the-periodic-table-what-are-the-advantages-of-long-form-of-periodic-table\" title=\"Question 1. Discuss the main features of long form of the periodic table. What are the advantages of long . form of periodic table?\">Question 1. Discuss the main features of long form of the periodic table. What are the advantages of long . form of periodic table?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-79\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-2-discuss-the-main-characteristics-of-four-blocks-of-elements-in-the-periodic-table-give-their-general-electronic-configuration\" title=\"Question 2. Discuss the main characteristics of four blocks of elements in the periodic table? Give their general electronic configuration.\">Question 2. Discuss the main characteristics of four blocks of elements in the periodic table? Give their general electronic configuration.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-80\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-3-define-electron-gain-enthalpy-what-are-its-units-discuss-the-factors-which-influence-the-electron-gain-enthalpy\" title=\"Question 3. Define electron gain enthalpy. What are its units? Discuss the factors which influence the electron gain enthalpy.\">Question 3. Define electron gain enthalpy. What are its units? Discuss the factors which influence the electron gain enthalpy.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-81\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-4-discuss-the-factors-that-influence-the-magnitude-of-ionization-enthalpy-what-are-the-general-trends-of-variation-of-ionization-enthalpy-in-the-periodic-table-explain\" title=\"Question 4. Discuss the factors that influence the magnitude of ionization enthalpy. What are the general trends of variation of ionization enthalpy in the periodic table? Explain.\">Question 4. Discuss the factors that influence the magnitude of ionization enthalpy. What are the general trends of variation of ionization enthalpy in the periodic table? Explain.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-82\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-5-a-how-does-atomic-radius-vary-in-group-in-the-periodic-table-b-explain-i-radius-of-cation-is-less-than-that-of-the-atom-ii-radius-of-anion-is-more-than-that-of-the-atom-iii-in-iso-electronic-ion-the-ionic-radii-decreases-with-increase-in-atomic-number\" title=\"Question 5. (a) How does atomic radius vary in group in the periodic table? (b) Explain (i) Radius of cation is less than that of the atom. (ii) Radius of anion is more than that of the atom. (iii) In iso-electronic ion, the ionic radii decreases with increase in atomic number.\">Question 5. (a) How does atomic radius vary in group in the periodic table? (b) Explain (i) Radius of cation is less than that of the atom. (ii) Radius of anion is more than that of the atom. (iii) In iso-electronic ion, the ionic radii decreases with increase in atomic number.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-83\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-1-the-highest-ionization-energy-is-exhibited-by-a-halogens-b-alkaline-earth-metals-c-transition-metals-d-noble-gases-question-2-which-of-the-following-oxides-is-neutral-a-sn02-b-co-c-al203-d-na20\" title=\"Question\u00a01. The highest ionization energy is exhibited by (a) halogens (b) alkaline earth metals (c) transition metals (d) noble gases Question 2. Which of the following oxides is neutral? (a) Sn02\u00a0(b) CO (c) Al203\u00a0(d) Na20\">Question\u00a01. The highest ionization energy is exhibited by (a) halogens (b) alkaline earth metals (c) transition metals (d) noble gases Question 2. Which of the following oxides is neutral? (a) Sn02\u00a0(b) CO (c) Al203\u00a0(d) Na20<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-84\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-3-which-of-the-following-is-arranged-in-order-of-increasing-radius-a-k-aq-%3c-na-aq-%3c-li-aq-b-k-aq-%3e-na-aq-%3e-zn2-aq-c-k-aq-%3e-li-aq-%3e-na-aq-d-li-aq-%3c-na-aq-%3c-k-aq\" title=\"Question 3. Which of the following is arranged in order of increasing radius? (a) K+\u00a0(aq) &lt; Na+\u00a0(aq) &lt; Li+\u00a0(aq) (b) K+\u00a0(aq) &gt; Na+\u00a0(aq) &gt; Zn2+\u00a0(aq) (c) K+\u00a0(aq) &gt; Li+\u00a0(aq) &gt; Na+\u00a0(aq) (d) Li+\u00a0(aq) &lt; Na+\u00a0(aq) &lt; K+\u00a0(aq)\">Question 3. Which of the following is arranged in order of increasing radius? (a) K+\u00a0(aq) &lt; Na+\u00a0(aq) &lt; Li+\u00a0(aq) (b) K+\u00a0(aq) &gt; Na+\u00a0(aq) &gt; Zn2+\u00a0(aq) (c) K+\u00a0(aq) &gt; Li+\u00a0(aq) &gt; Na+\u00a0(aq) (d) Li+\u00a0(aq) &lt; Na+\u00a0(aq) &lt; K+\u00a0(aq)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-85\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-4-what-is-the-electronic-configuration-of-the-elements-of-group-14-a-ns2-np4-b-ns2-np6-c-ns2-np2-d-ns2\" title=\"Question 4. What is the electronic configuration of the elements of group 14? (a) ns2\u00a0np4\u00a0(b) ns2\u00a0np6\u00a0(c) ns2\u00a0np2\u00a0(d) ns2\">Question 4. What is the electronic configuration of the elements of group 14? (a) ns2\u00a0np4\u00a0(b) ns2\u00a0np6\u00a0(c) ns2\u00a0np2\u00a0(d) ns2<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-86\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-5-among-the-following-elements-which-has-the-least-electron-affinity-a-phosphorous-b-oxygen-c-sulphur-d-nitrogen\" title=\"Question 5. Among the following elements, which has the least electron affinity? (a) Phosphorous (b) Oxygen (c) Sulphur (d) Nitrogen\">Question 5. Among the following elements, which has the least electron affinity? (a) Phosphorous (b) Oxygen (c) Sulphur (d) Nitrogen<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-87\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-6-in-halogens-which-of-the-following-increases-from-iodine-to-fluorine-a-bond-length-b-electronegativity-c-the-ionization-energy-of-the-element-d-oxidizing-power\" title=\"Question 6. In halogens, which of the following, increases from iodine to fluorine? (a) Bond length (b) Electronegativity (c) The ionization energy of the element (d) Oxidizing power\">Question 6. In halogens, which of the following, increases from iodine to fluorine? (a) Bond length (b) Electronegativity (c) The ionization energy of the element (d) Oxidizing power<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-88\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-7-diagonal-relationships-are-shown-by-a-be-and-a1-b-mg-and-a1-c-li-and-mg-d-b-and-p\" title=\"Question 7. Diagonal relationships are shown by (a) Be and A1 (b) Mg and A1 (c) Li and Mg (d) B and P\">Question 7. Diagonal relationships are shown by (a) Be and A1 (b) Mg and A1 (c) Li and Mg (d) B and P<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-89\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-8-which-of-the-following-species-are-not-known-a-agoh-b-pbi4-c-pi5-d-sh6-e-all-of-the-above\" title=\"Question 8. Which of the following species are not known? (a) AgOH (b) PbI4\u00a0(c) PI5\u00a0(d) SH6 (e) All of the above\">Question 8. Which of the following species are not known? (a) AgOH (b) PbI4\u00a0(c) PI5\u00a0(d) SH6 (e) All of the above<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-90\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-9-which-one-of-the-following-is-isoelectronic-with-ne-a-n3-b-mg2-c-al3-dall-of-the-above\" title=\"Question 9. Which one of the following is isoelectronic with Ne? (a) N3-\u00a0(b) Mg2+\u00a0(c) Al3+\u00a0(d)all of the above\">Question 9. Which one of the following is isoelectronic with Ne? (a) N3-\u00a0(b) Mg2+\u00a0(c) Al3+\u00a0(d)all of the above<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-91\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-10which-element-has-smallest-size-a-b-b-n-c-al-d-p\" title=\"Question 10.Which element has smallest size? (a) B (b) N (c) Al (d) P\">Question 10.Which element has smallest size? (a) B (b) N (c) Al (d) P<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-92\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#v-hots-questions-question-1-arrange-the-following-as-stated-i-n2-02-f2-cl2increasing-order-of-bond-dissociation-energy-ii-f-cl-br-i-increasing-order-of-electron-gain-enthalpy-iii-f2-n2-cl2-o2increasing-order-of-bond-length\" title=\"V. Hots Questions Question 1. Arrange the following as stated: (i) N2, 02, F2, Cl2(Increasing order of bond dissociation energy) (ii) F, Cl, Br, I (Increasing order of electron gain enthalpy) (iii)\u00a0F2, N2, Cl2, O2(Increasing order of bond length).\">V. Hots Questions Question 1. Arrange the following as stated: (i) N2, 02, F2, Cl2(Increasing order of bond dissociation energy) (ii) F, Cl, Br, I (Increasing order of electron gain enthalpy) (iii)\u00a0F2, N2, Cl2, O2(Increasing order of bond length).<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-93\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-2-the-first-ionisation-enthalpy-of-magnesium-is-higher-than-that-of-sodium-on-the-other-hand-the-second-ionisation-enthalpy-of-sodium-is-very-much-higher-than-that-of-magnesium-explain\" title=\"Question 2. The first ionisation enthalpy of magnesium is higher than that of sodium. On the other hand, the second ionisation enthalpy of sodium is very much higher than that of magnesium. Explain.\">Question 2. The first ionisation enthalpy of magnesium is higher than that of sodium. On the other hand, the second ionisation enthalpy of sodium is very much higher than that of magnesium. Explain.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-94\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#question-3-give-reasons-i-ie1-of-sodium-is-lower-than-that-of-magnesium-whereas-ie2-of-sodium-is-higher-than-that-of-magnesium-ii-noble-gases-have-positive-value-of-electron-gain-enthalpy\" title=\"Question 3. Give reasons: (i) IE1\u00a0of sodium is lower than that of magnesium whereas\u00a0IE2\u00a0of sodium is higher than that of magnesium. (ii) Noble gases have positive value of electron gain enthalpy.\">Question 3. Give reasons: (i) IE1\u00a0of sodium is lower than that of magnesium whereas\u00a0IE2\u00a0of sodium is higher than that of magnesium. (ii) Noble gases have positive value of electron gain enthalpy.<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-95\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#faq-ncert-solutions-for-class-11-chemistry-chapter-3-classification-of-elements-and-periodicity-in-properties\" title=\"FAQ: NCERT Solutions For Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties\">FAQ: NCERT Solutions For Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-96\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#can-i-download-ncert-solutions-for-class-11-chemistry-chapter-3-for-free\" title=\"Can I download NCERT Solutions For Class 11 Chemistry Chapter 3 for free? \">Can I download NCERT Solutions For Class 11 Chemistry Chapter 3 for free? <\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-97\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#what-is-the-name-of-chapter-3-in-chemistry-class-11\" title=\"What is the name of Chapter 3 in chemistry class 11?\">What is the name of Chapter 3 in chemistry class 11?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-98\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#what-are-the-topics-included-in-periodic-trends-in-properties-of-elements-of-ncert-solutions-for-class-11-chemistry-chapter-3\" title=\"What are the topics included in Periodic Trends In Properties Of Elements of NCERT Solutions For Class 11 Chemistry Chapter 3? \">What are the topics included in Periodic Trends In Properties Of Elements of NCERT Solutions For Class 11 Chemistry Chapter 3? <\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-99\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#what-is-periodic-properties-ncert-solutions-for-class-11-chemistry-chapter-3\" title=\"What is periodic properties NCERT Solutions For Class 11 Chemistry Chapter 3?\">What is periodic properties NCERT Solutions For Class 11 Chemistry Chapter 3?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-100\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/#how-many-elements-are-present-now\" title=\"How many elements are present now?\">How many elements are present now?<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"ncert-solutions-for-class-11-chemistry-chapter-3-classification-of-elements-and-periodicity-in-properties\"><\/span><strong>NCERT Solutions For Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Looking through the internet to get some solid study material to sit for chemistry exam preparation is not a hard task anymore, for we bring you NCERT Solutions For Class 11 Chemistry Chapter 3 pdf.<\/p>\n<p>Download NCERT Solutions For Class 11 Chemistry Chapter 3 pdf from here and accommodate yourself with some effortless yet poignant course structure.<\/p>\n<p>Download NCERT course material in your device like smartphone, desktop or laptop and start with our exam preparation anytime anywhere.<\/p>\n<p>Moreover, the Hindi medium student grab your copy of NCERT solutions for class 11 chemistry chapter 3 pdf download in Hindi from here to have a rigorous understanding of the subject in no time.<\/p>\n<p>You can download\u00a0CBSE NCERT Solutions for Class 11 Chemistry Chapter 3 from below.<\/p>\n<p><a href=\"https:\/\/www.kopykitab.com\/blog\/wp-content\/uploads\/2021\/07\/chapter_3_classification_of_elements_and_periodicity.pdf\">NCERT Solutions For Class 11 Chemistry Chapter 3<\/a><\/p>\n<p>\u00a0<\/p>\n<div id=\"example1\" style=\"text-align: justify\">\u00a0<\/div>\n<p style=\"text-align: justify\">.pdfobject-container { height: 500px;}<br \/>.pdfobject { border: 1px solid #666; }<\/p>\n<p style=\"text-align: justify\"><br \/>PDFObject.embed(&#8220;https:\/\/www.kopykitab.com\/blog\/wp-content\/uploads\/2021\/07\/chapter_3_classification_of_elements_and_periodicity.pdf&#8221;, &#8220;#example1&#8221;);<\/p>\n<h2><span class=\"ez-toc-section\" id=\"what-will-you-learn-in-cbse-class-11-chemistry-chapter-3\"><\/span>What will you learn in CBSE Class 11 Chemistry Chapter 3?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>NCERT Solutions For Class 11 Chemistry Chapter 3 comes with one of the vital portions of the syllabus that acts pretty important for both class 11 and class 12.<\/p>\n<p>Additionally, with strong preparation base, students will get tremendous help while appearing for JEE and NEET. The topics covered in this chapter are as follows-<\/p>\n<ul>\n<li>Genesis of periodic classification<\/li>\n<li>Modern periodic law and the present form of the periodic table<\/li>\n<li>Nomenclatures of elements with atomic number greater than 100<\/li>\n<li>Electronic configurations of elements and the periodic table<\/li>\n<li>The s-block, p-block, d-block, and f-block elements<\/li>\n<li>Metals, non-metals and metalloids<\/li>\n<li>Periodic trends in properties of elements<\/li>\n<li>Trends in physical properties<\/li>\n<li>Trends in chemical properties<\/li>\n<li>Trends in chemical reactivity<\/li>\n<\/ul>\n<h4><span class=\"ez-toc-section\" id=\"types-of-questions-that-students-get-from-this-chapter-are-listed-down\"><\/span><strong>Types of questions that students get from this chapter are listed down-<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h4>\n<ol>\n<li>Question on the classification of elements<\/li>\n<li>Questions on periodic tables along with nomenclature of elements from Z&gt;100<\/li>\n<li>Questions on quantum functions along with electronic configuration.<\/li>\n<li>Some more other important questions are on Atomic\/ionic radii, ionization enthalpy, electron affinity, electronegativity and lastly reactivity of elements and more.<\/li>\n<\/ol>\n<h2><span class=\"ez-toc-section\" id=\"subtopics-from-ncert-solutions-for-class-11-chemistry-chapter-3\"><\/span><strong>Subtopics From NCERT Solutions For Class 11 Chemistry Chapter 3<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Subtopics of NCERT Solutions For Class 11 Chemistry Chapter 3 that students get to study in this chapter are,<strong>\u00a0<\/strong><\/p>\n<ul>\n<li>Why Do We Need To Classify Elements?<\/li>\n<li>Genesis Of Periodic Classification<\/li>\n<li>Modern Periodic Law And The Present Form Of The Periodic Table<\/li>\n<li>Nomenclature Of Elements With Atomic Numbers &gt; 100<\/li>\n<li>Electronic Configurations Of Elements And The Periodic Table<\/li>\n<li>Electronic Configurations And Types Of Elements: 5-, P-, D-, F- Blocks Ex\n<ul>\n<li>The S-block Elements<\/li>\n<li>The P-block Elements<\/li>\n<li>The D-block Elements (Transition Elements)<\/li>\n<li>The F-block Elements (Inner-transition Elements)<\/li>\n<li>Metals, Non-metals And Metalloids<\/li>\n<\/ul>\n<\/li>\n<li>Periodic Trends In Properties Of Elements\n<ul>\n<li>Trends in Physical Properties<\/li>\n<li>Periodic Trends In Chemical Properties<\/li>\n<li>Periodic Trends And Chemical Reactivity.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"benefits-of-ncert-solutions-for-class-11-chemistry-chapter-3\"><\/span><strong>Benefits of NCERT Solutions For Class 11\u00a0Chemistry Chapter 3<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ol>\n<li>NCERT in collaboration with CBSE is doing great for the aspiring students out there. Additionally, the easy language base is effortlessly making the chapters get in fast and better for the students studying in 11th standard.<\/li>\n<li>These NCERT Solutions For Class 11 Chemistry Chapter 3 are a helping hand beside the classroom textbooks, so, students get the opportunity to wrap up the syllabus much before time.<\/li>\n<li>With quick completion of the chapters, students get several revision sessions to attempt which ultimately boosts their confidence for performing excellently during the actual exam.<\/li>\n<li>Moreover the more you go through the NCERT Solutions For Class 11 Chemistry Chapter 3, the better you get to understand your merit status, thus students get abundant scopes to work on their weakness on the subject, which again helps you a lot in performing brilliantly in your exam.<\/li>\n<\/ol>\n<p>We have chalked down the essentials for you to invest your quality time in chemistry preparation. We hope you do great for your upcoming exam. But still, if you come across any uncertainties make sure to ask us since we are here to solve your problem out.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"access-ncert-solutions-for-class-11-chemistry-chapter-3\"><\/span>Access <strong>NCERT Solutions For Class 11\u00a0Chemistry Chapter 3<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"question-1-what-is-the-basic-theme-of-organisation-in-the-periodic-table\"><\/span><strong>Question 1. What is the basic theme of organisation in the periodic table?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0The basic theme of organisation of elements in the periodic table is to simplify and systematize the study of the properties of all the elements and millions of their compounds. This has made the study simple because the properties of elements are now studied in form of groups rather than individually.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-2-which-important-property-did-mendeleev-use-to-classify-the-elements-in-this-periodic-table-and-did-he-stick-to-that\"><\/span><strong>Question 2. Which important property did Mendeleev use to classify the elements in this periodic table and did he stick to that?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Mendeleev used atomic weight as the basis of classification of elements in the periodic table. He did stick to it and classify elements into groups and periods.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-3-what-is-the-basic-difference-in-approach-between-mendeleev%e2%80%99s-periodic-law-and-the-modem-periodic-law\"><\/span><strong>Question 3. What is the basic difference in approach between Mendeleev\u2019s Periodic Law and the Modem Periodic Law?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0The basic difference in approach between Mendeleev\u2019s Periodic Law and Modem Periodic Law is the change in basis of classification of elements from atomic weight to atomic number.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-4-on-the-basis-of-quantum-numbers-justify-that-the-sixth-period-of-the-periodic-table-should-have-32-elements\"><\/span><strong>Question 4. On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong> The sixth period corresponds to sixth shell. The orbitals present in this shell are 6s, 4f, 5p, and 6d. The maximum number of electrons which can be present in these subshell is 2 + 14 + 6 + 10 = 32. Since the number of elements in a period corresponds to the number of electrons in the shells, therefore, sixth period should have a maximum of 32 elements.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-5-in-terms-of-period-and-group-where-will-you-locate-the-element-with-z-114\"><\/span><strong>Question 5. In terms of period and group where will you locate the element with z = 114?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Period \u2013 7 and Group -14 Block-p.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-6-write-the-atomic-number-of-the-element-present-in-the-third-period-and-seventeenth-group-of-the-periodic-table\"><\/span><strong>Question 6. Write the atomic number of the element present in the third period and seventeenth group of the periodic table.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0The element is chlorine (Cl) with atomic number (Z) = 17.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-7-which-element-do-you-think-would-have-been-named-by-ilawrence-berkeley-laboratory-iiseaborg%e2%80%99s-group\"><\/span><strong>Question 7. Which element do you think would have been named by<\/strong><br \/><strong>(i)Lawrence Berkeley Laboratory<\/strong><br \/><strong>(ii)Seaborg\u2019s group?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(i) Lawrencium (Lr) with atomic number (z) = 103<br \/>(ii) Seaborgium (Sg) with atomic number (z) = 106.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-8-why-do-elements-in-the-same-group-have-similar-physical-and-chemical-properties\"><\/span><strong>Question 8. Why do elements in the same group have similar physical and chemical properties?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0The elements in a group have same valence shell electronic configuration and hence have similar physical and chemical properties.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-9-what-does-atomic-radius-and-ionic-radius-really-mean-to-you\"><\/span><strong>Question 9. What does atomic radius and ionic radius really mean to you?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>\u00a0<strong>Atomic radius.<\/strong>\u00a0The distance from the centre of nucleus to the outermost shell o electrons in the atom of any element is called its atomic radius. It refers to both covalen or metallic radius depending on whether the element is a non-metal or a metal.<\/p>\n<p><strong>Ionic radius.<\/strong>\u00a0The Ionic radii can be estimated by measuring the distances between cations and anions in ionic crystals.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-10-how-do-atomic-radius-vary-in-a-period-and-in-a-group-how-do-you-explain-the-variation\"><\/span><strong>Question 10. How do atomic radius vary in a period and in a group? How do you explain the variation?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Within a group Atomic radius increases down the group.<br \/><strong>Reason.<\/strong>\u00a0This is due to continuous increases in the number of electronic shells or orbit numbers in the structure of atoms of the elements down a group.<br \/><strong>Variation across period.<\/strong><br \/><strong>Atomic Radii.<\/strong>\u00a0From left to right across a period atomic radii generally decreases due<br \/>to increase in effective nuclear charge from left to right across a period.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-11-what-do-you-understand-by-isoelectronic-species-name-a-species-that-will-be-iso-electronic-with-each-of-the-following-atoms-or-ions-i-f%e2%80%93ii-ar-iii-mg2iv-rb\"><\/span><strong>Question 11. What do you understand by isoelectronic species? Name a species that will be iso electronic with each of the following atoms or ions.<\/strong><br \/><strong>(i) F<sup>\u2013<\/sup>(ii) Ar (iii) Mg<sup>2+<\/sup>(iv)\u00a0Rb<sup>+<\/sup><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>\u00a0Isoelectronic species are those species (atoms\/ions) which have same number of<br \/>electrons. The isoelectronic species are:<br \/>(i)Na<sup>+<\/sup>\u00a0(iii) Na<sup>+<\/sup><br \/>(ii)K<sup>+<\/sup> (iv) Sr<sup>2+<\/sup><\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-12-consider-the-following-species-n3-o2-f%e2%80%93-na-mg2-al3-a-what-is-common-in-them-b-arrange-them-in-order-of-increasing-ionic-radii\"><\/span><strong>Question 12. Consider the following species:<\/strong><br \/><strong>N<sup>3-,\u00a0<\/sup>O<sup>2-,<\/sup>\u00a0F<sup>\u2013<\/sup>, Na<sup>+<\/sup>, Mg<sup>2+,<\/sup>\u00a0Al<sup>3+<\/sup><\/strong><br \/><strong>(a) What is common in them?<\/strong><br \/><strong>(b) Arrange them in order of increasing ionic radii?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>\u00a0(a) All of them are isoelectronic in nature and have 10 electrons each.<br \/>(b) In isoelectronic species, greater the nuclear charge, lesser will be the atomic or ionic radius.<br \/>Al<sup>3+<\/sup>\u00a0&lt; Mg<sup>2+<\/sup>\u00a0&lt; Na<sup>+<\/sup>\u00a0&lt; F<sup>\u2013<\/sup>\u00a0&lt; O<sup>2-<\/sup>\u00a0&lt; N<sup>3-<\/sup><\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-13-explain-why-cation-are-smaller-and-anions-larger-in-radii-than-their-parent-atoms\"><\/span><strong>Question 13. Explain why cation are smaller and anions larger in radii than their parent atoms?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0A cation is smaller than the parent atom because it has fewer electrons while its nuclear<br \/>charge remains the same. The size of anion will be larger than that of parent atom<br \/>because the addition of one or more electrons would result in increased repulsion among the electrons and a decrease in effective nuclear charge.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-14-what-is-the-significance-of-the-terms-%e2%80%93-isolated-gaseous-atom-and-ground-state-while-defining-the-ionization-enthalpy-and-electron-gain-enthalpyhint-requirements-for-comparison-purposes\"><\/span><strong>Question 14. What is the significance of the terms \u2013 isolated gaseous atom and ground state while defining the ionization enthalpy and electron gain enthalpy?[Hint: Requirements for comparison purposes]<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong><\/p>\n<ul>\n<li>Significance of term \u2018isolated gaseous atom\u2019. The atoms in the gaseous state are far separated in the sense that they do not have any mutual attractive and repulsive interactions.<\/li>\n<li>These are therefore regarded as isolated atoms. In this state the value of ionization enthalpy and electron gain enthalpy are not influenced by the presence of the other atoms.<\/li>\n<li>It is not possible to express these when the atoms are in the ; liquid or solid state due to the presence of inter atomic forces.<\/li>\n<li>Significance of ground state. Ground state of the atom represents the normal \u2013 energy state of an atom. It means electrons in a particular atom are in the lowest energy state and they neither lose nor gain electron.<\/li>\n<li>Both ionisation enthalpy and I electron gain enthalpy are generally expressed with respect to the ground state of an atom only.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"question-15-energy-of-an-electron-in-the-ground-state-of-the-hydrogen-atom-is-218-x-10-18-calculate-the-ionization-enthalpy-of-atomic-hydrogen-in-terms-of-jmol-1hint-apply-the-idea-of-mole-concept-to-derive-the-answer\"><\/span><b>Question 15. Energy of an electron in the ground state of the hydrogen atom is- 2.18 x 10<\/b><sup style=\"font-weight: bold\">-18<\/sup><b>\u00a0Calculate\u00a0the ionization enthalpy of atomic hydrogen in terms of JMol<\/b><sup style=\"font-weight: bold\">-1<\/sup><b>.[Hint: Apply the idea of mole concept to derive the answer],<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>\u00a0The ionisation enthalpy is for 1 mole atoms. Therefore, ground state energy of the , atoms may be expressed as E (ground state) = (\u00a0\u2013 2.18 x 10<sup>-18<\/sup>\u00a0J) x(6.022 x 10<sup>23<\/sup>\u00a0mol<sup>-1<\/sup>)= -1.312 x 10<sup>6<\/sup>\u00a0J mol<sup>-1<\/sup><br \/>Ionisation enthalpy =E<sub>\u221e<\/sub><sub>\u2013<\/sub>E\u00a0ground state<br \/>= 0-(-1.312 x 10<sup>6<\/sup>mol<sup>-1<\/sup>)<br \/>= 1.312 x 10<sup>6<\/sup>\u00a0J mol<sup>-1<\/sup>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-16-among-the-second-period-elements-the-actual-ionization-enthalpies-are-in-the-order-li\"><\/span><strong>Question 16. Among the second period elements, the actual ionization enthalpies are in the order: Li &lt;B&lt; Be &lt;C&lt;0&lt;KI&lt;F&lt; Ne<\/strong><br \/><strong>Explain why<\/strong><br \/><strong>(i) Be has higher \u2206<sub>i<\/sub>H<sub>1<\/sub>than B ?<\/strong><br \/><strong>(ii) O has lower \u2206<sub>i<\/sub>H<sub>1<\/sub>\u00a0than N and F?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(i) In case of Be (1s<sup>2<\/sup>\u00a02s<sup>2<\/sup>) the outermost electron is present in 2s-orbital while in B (1s<sup>2<\/sup>\u00a02s<sup>2<\/sup>\u00a02p<sup>1<\/sup>) it is present in 2p-orbital. Since 2s \u2013 electrons are more strongly attracted by the nucleus than 2p-electrons, therefore, lesser amount of energy is required to knock out a 2p-electron than a 2s \u2013 electron. Consequently, At of Be is higher than that \u2206<sub>i<\/sub>H<sub>1<\/sub>\u00a0of B.<br \/>(ii) The electronic configuration of<br \/>N<sub>7<\/sub>\u00a0= 1s<sup>2\u00a0<\/sup>2s<sup>2<\/sup>\u00a02p<sub>x<\/sub><sup>1<\/sup>\u00a02p<sub>y<\/sub><sup>1<\/sup>\u00a02p<sub>z<\/sub><sup>1<\/sup><br \/>O<sub>8<\/sub>\u00a0=1s<sup>2<\/sup>\u00a02s<sup>2<\/sup>\u00a02p<sub>x<\/sub><sup>1<\/sup>\u00a02p<sub>y<\/sub><sup>1<\/sup>\u00a02p<sub>z<\/sub><sup>1<\/sup><br \/>We can see that in case of nitrogen 2p-orbitals are exactly half filled. Therefore, it is difficult to remove an electron from N than from O. As a result \u2206<sub>i<\/sub>H<sub>1<\/sub>\u00a0of N is higher than that of O.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-17-how-would-you-explain-the-fact-that-the-first-ionization-enthalpy-of-sodium-is-lower-than-that-of-magnesium-but-its-second-ionization-enthalpy-is-higher-than-that-of-magnesium\"><\/span><strong>Question 17. How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>\u00a0Electronic configuration of Na and Mg are<br \/>Na = 1s<sup>2<\/sup>\u00a02s<sup>2<\/sup>\u00a02p<sup>6<\/sup>\u00a03s<sup>1<\/sup><br \/>Mg = 1s<sup>2<\/sup>\u00a02s<sup>2<\/sup>\u00a02p<sup>6<\/sup>\u00a03s<sup>2<\/sup><br \/>First electron in both cases has to be removed from 3s-orbital but the nuclear charge of Na (+ 11) is lower than that of Mg (+ 12) therefore first ionization energy of sodium is lower than that of magnesium.<\/p>\n<p>After the loss of first electron, the electronic configuration of<br \/>Na<sup>+<\/sup>\u00a0= 1s<sup>2<\/sup>\u00a02s<sup>2<\/sup>\u00a02p<sup>6<\/sup><br \/>Mg<sup>+<\/sup>\u00a0= 1s<sup>2<\/sup>\u00a02s<sup>2<\/sup>\u00a02p<sup>6<\/sup>\u00a03s<sup>1<\/sup><br \/>Here electron is to be removed from inert (neon) gas configuration which is very stable and hence removal of second electron requires more energy in comparison to Mg.<br \/>Therefore, second ionization enthalpy of sodium is higher than that of magnesium.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-18-what-are-the-various-factors-due-to-which-the-ionization-enthalpy-of-the-main-group-elements-tends-to-decrease-down-the-group\"><\/span><strong>Question 18. What are the various factors due to which the ionization enthalpy of the main group elements tends to decrease down the group?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong> Atomic size. With the increase in atomic size, the number of electron shells increase. Therefore, the force that binds the electrons with the nucleus decreases.<\/p>\n<p>The ionization enthalpy thus decreases with the increase in atomic size. Screening or shielding effect of inner shell electron.<\/p>\n<p>With the addition of new shells, the number of inner electron shells which shield the valence electrons increases. As a result, the force of attraction of the nucleus for the valence electrons further decreases and hence the ionization enthalpy decreases. \u2018<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-19-the-first-ionization-enthalpy-values-in-kj-mol-1-of-group-13-elements-are-b-al-ga-in-tl-801-577-579-558-589-how-would-you-explain-this-deviation-from-the-general-trend\"><\/span><strong>Question 19. The first ionization enthalpy values (in kJ mol\u00a0<sup>-1<\/sup>) of group 13 elements are:<\/strong><br \/><strong>B Al Ga In Tl<\/strong><br \/><strong>801 577 579 558 589<\/strong><br \/><strong>How would you explain this deviation from the general trend?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0The decrease in\u00a0\u2206<sub>i<\/sub>H<sub>1\u00a0<\/sub>value from B to Al is due to the bigger size of Al.<br \/>In Ga there is 10 3d electrons which do not screen as is done by S and P electrons.<\/p>\n<p>Therefore, there is an unexpected increase in the magnitude of effective nuclear charge resulting in increased \u2206<sub>i<\/sub>H<sub>1\u00a0<\/sub>values. <span style=\"font-size: inherit;background-color: initial\">The same is with into Tl. The later has fourteen \u2206f\u00a0electrons with very poor shielding effect. This also increases, the effective nuclear charge thus the value of \u2206<\/span><sub style=\"background-color: initial\">i<\/sub><span style=\"font-size: inherit;background-color: initial\">H<\/span><sub style=\"background-color: initial\">1\u00a0<\/sub><span style=\"font-size: inherit;background-color: initial\">increases.<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-20-which-of-the-following-pairs-of-elements-would-have-a-move-negative-electron-gain-enthalpy-i-o-or-f-ii-f-or-cl\"><\/span><strong>Question 20. Which of the following pairs of elements would have a move negative electron gain enthalpy?\u00a0<\/strong><strong>(i) O or F (ii) F or Cl.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(i) O or F. Both O and F lie in 2nd period. As we move from O to F the atomic size decreases.<br \/>Due to smaller size of F nuclear charge increases.<br \/>Further, gain of one electron by<br \/>F \u2014&gt; F<sup>\u2013<\/sup><br \/>F~ ion has inert gas configuration, While the gain of one electron by<br \/>0-&gt;O<sup>\u2013<\/sup><br \/>gives CT ion which does not have stable inert gas configuration, consequently, the energy released is much higher in going from<br \/>F -&gt;F<sup>\u2013<\/sup><br \/>than going from O \u2014&gt;O<sup>\u2013<\/sup><br \/>In other words electron gain enthalpy of F is much more negative than that of oxygen.<br \/>(ii) The negative electron gain enthalpy of Cl (\u2206 eg H = \u2013 349 kj mol-1) is more than that of F (\u2206 eg H = \u2013 328 kJ\u00a0mol\u00a0<sup>-1<\/sup>).<br \/>The reason for the deviation is due to the smaller size of F. Due to its small size, the electron repulsions in the relatively compact 2p-subshell are comparatively large and hence the attraction for incoming electron is less as in the case of Cl.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-21-would-you-expect-the-second-electron-gain-enthalpy-of-o-as-positive-more-negative-or-less-negative-than-the-first-justify-your-answer\"><\/span><strong>Question 21. Would you expect the second electron gain enthalpy of O as positive, more negative or less negative than the first? Justify your answer.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong><strong>\u00a0For oxygen atom:<\/strong><br \/>O (g) + e<sup>\u2013<\/sup>\u00a0\u2014&gt; O<sup>\u2013<\/sup>\u00a0(g) (\u2206 eg H = \u2013 141 kJ mol\u00a0<sup>-1<\/sup>)<br \/>O<sup>\u2013<\/sup>\u00a0(g) + e<sup>\u2013<\/sup>\u00a0\u2014&gt; O\u00a0<sup>2-<\/sup>\u00a0(g) (\u2206 eg H = + 780 kJ mol\u00a0<sup>-1<\/sup>)<br \/>The first electron gain enthalpy of oxygen is negative because energy is released when a gaseous atom accepts an electron to form monovalent anion.<\/p>\n<p>The second electron gain enthalpy is positive because energy is needed to overcome the force of repulsion between monovalent anion and second incoming electron.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-22-what-is-basic-difference-between-the-terms-electron-gain-enthalpy-and-electro-negativity\"><\/span><strong>Question 22. What is basic difference between the terms electron gain enthalpy and electro negativity?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>Electron gain enthalpy refers to tendency of an isolated gaseous atom to accept an additional electron to form a negative ion. Whereas electronegativity refers to tendency of the atom of an element to attract shared pair of electrons towards it in a covalent bond.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"23-how-would-you-react-to-the-statement-that-the-electronegativity-of-on-pauling-scale-is-30-in-all-the-nitrogen-compounds\"><\/span><strong>23. How would you react to the statement that the electronegativity of on Pauling scale is 3.0 in all the nitrogen compounds?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Ans.<\/strong>\u00a0On Pauling scale, the electronegativity of nitrogen, (3.0) indicates that it is sufficiently electronegative. But it is not correct to say that the electronegativity of nitrogen in all the compounds is 3.<\/p>\n<p>It depends upon its state of hybridisation in a particular compound, greater the percentage of s-character, more will be the electronegativity of the element.<\/p>\n<p>Thus, the electronegativity of nitrogen increases in moving from SP<sup>3<\/sup>\u00a0hybridised orbitals to SP hybridised orbitals i.e., as\u00a0SP<sup>3\u00a0<\/sup>&lt; SP<sup>2<\/sup>\u00a0&lt; SP.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-24-describe-the-theory-associated-with-the-radius-of-an-atom-as-it-a-gains-an-electron-b-loses-an-electron\"><\/span><strong>Question 24. Describe the theory associated with the radius of an atom as it:<\/strong><br \/><strong>(a) gains an electron (b) loses an electron ?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong><\/p>\n<ul>\n<li>Gain of an electron leads to the formation of an anion. The size of an anion will be larger than that of the parent atom because the addition of one or more electrons would result in increased repulsion among electrons and decrease in effective nuclear charge.<br \/>This the ionic radius of fluoride ion (F<sup>\u2013<\/sup>) is 136 pm whereas atomic radius of Fluorine (F) is only 64 pm.<\/li>\n<li>Loss of an electron from an atom results in the formation of a cation. A cation is smaller than its parent atom because it has fomer electrons while its nuclear charge remains the same.<\/li>\n<li>For example, The atomic radius of sodium (Na) is 186 pm and atomic radius of sodium ion (Na<sup>+<\/sup>) = 95 pm.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"question-25-would-you-expect-the-first-ionization-enthalpies-of-two-isotopes-of-the-same-element-to-be-the-same-or-different-justify-your-answer\"><\/span><strong>Question 25. Would you expect the first ionization enthalpies of two isotopes of the same element to be the same or different? Justify your answer.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Ionization enthalpy, among other things, depends upon the electronic configuration (number of electrons) and nuclear charge (number of protons). Since isotopes of an element have the same electronic configuration and same nuclear charge, they have same ionization enthalpy.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-26-what-are-major-differences-between-metals-and-non-metals\"><\/span><strong>Question 26. What are major differences between metals and non-metals?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong><br \/><img src=\"https:\/\/c2.staticflickr.com\/8\/7236\/27399607444_b7d03362aa_o.png\" alt=\"ncert-solutions-for-class-11-chemistry-chapter-3-classification-of-elements-and-periodicity-in-properties-1\" width=\"739\" height=\"179\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-27-use-periodic-table-to-answer-the-following-questions-a-identify-the-element-with-five-electrons-in-the-outer-subshell-b-identify-the-element-that-would-tend-to-lose-two-electrons-c-identify-the-element-that-would-tend-to-gain-two-electrons\"><\/span><strong>Question 27. Use periodic table to answer the following questions:<\/strong><br \/><strong>(a) Identify the element with five electrons in the outer subshell.<\/strong><br \/><strong>(b) Identify the element that would tend to lose two electrons.<\/strong><br \/><strong>(c) Identify the element that would tend to gain two electrons.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>\u00a0(a) Element belonging to nitrogen family (group 15) e.g., nitrogen.<br \/>(b) Element belonging to alkaline earth family (group 2) e.g., magnesium.<br \/>(c) Element belonging to oxygen family (group 16) e.g., oxygen.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-28-the-increasing-order-of-reactivity-among-group-1-elements-is-li-%3c-na-%3c-k-%3c-rb-%3c-cs-whereas-that-of-group-17-is-f-%3e-cl-%3e-br-%3e-i-explain\"><\/span><strong>Question 28. The increasing order of reactivity among group 1 elements is Li &lt; Na &lt; K &lt; Rb &lt; Cs whereas that of group 17 is F &gt; Cl &gt; Br &gt; I. Explain?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>\u00a0The elements of Group I have only one electron in their respective valence shells and thus have a strong tendency to lose this electron. The tendency to lose electrons in turn, depends upon the ionization enthalpy.<\/p>\n<p>Since the ionization enthalpy decreases down the group therefore, the reactivity of group 1 elements increases in the same order Li &lt; Na &lt; K &lt; Rb &lt; Cs.<\/p>\n<p>In contrast, the elements of group 17 have seven electrons in their respective valence shells and thus have strong tendency to accept one more electron to make stable configuration. It is linked with electron gain enthalpy and electronegativity.<\/p>\n<p>Since both of them decreases down the group, the reactivity therefore decreases.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-29-write-the-general-electronic-configuration-of-s%e2%80%93-p%e2%80%93-d%e2%80%93-and-f-block-elements\"><\/span><strong>Question 29. Write the general electronic configuration of s<sup>\u2013\u00a0<\/sup>p<sup>\u2013\u00a0<\/sup>d<sup>\u2013<\/sup>, and f-block elements?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(i) s-Block elements:\u00a0ns\u00a0<sup>1-2\u00a0<\/sup>where n = 2 \u2013 7.<br \/>(ii) p-Block elements:\u00a0ns<sup>2<\/sup>\u00a0np<sup>1-6\u00a0<\/sup>where n = 2-6.<br \/>(iii) d-Block elements:(n \u2013 1) d<sup>1-10\u00a0<\/sup>ns\u00a0<sup>0-2 <\/sup>where n = 4-7.<br \/>(iv) f-Block elements:\u00a0(n \u2013 2) f<sup>0-14\u00a0<\/sup>(n -1) d<sup>0-1\u00a0<\/sup>ns<sup>2<\/sup>where n = 6 \u2013 7.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-30-assign-the-position-of-the-element-having-outer-electronic-configuration-i-ns2-np4-for-n-3-ii-n-%e2%80%93-1-d2-ns2-for-n-4-and-iii-n-%e2%80%93-2-f7-n-%e2%80%93-1-d1-ns2-for-n-6-in-the-periodic-table\"><\/span><strong>Question 30. Assign the position of the element having outer electronic configuration,<\/strong><br \/><strong>(i) ns<sup>2<\/sup>\u00a0np<sup>4<\/sup>\u00a0for n = 3 (ii) (n \u2013 1) d<sup>2<\/sup>\u00a0ns<sup>2<\/sup>\u00a0for n = 4 and (iii) (n \u2013 2) f<sup>7<\/sup>\u00a0(n \u2013 1) d<sup>1<\/sup>\u00a0ns<sup>2<\/sup>\u00a0for n = 6 in the periodic table?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(i) n = 3<br \/>Thus element belong to 3rd period, p-block element.<br \/>Since the valence shell contains = 6 electrons, group No = 10 + 6 = 16 configuration =1s<sup>2\u00a0<\/sup>2s<sup>2<\/sup>\u00a02p<sup>6<\/sup>\u00a03s<sup>2<\/sup>\u00a03p<sup>4<\/sup> element name is sulphur.<br \/>(ii) n = 4<br \/>Means element belongs to 4th period belongs to group 4 as in the valence shell (2 + 2) = 4 electrons.<br \/>Electronic configuration.=1s<sup>2<\/sup>\u00a02s<sup>2<\/sup>\u00a02p<sup>6<\/sup>\u00a03s<sup>2<\/sup>\u00a03p<sup>6<\/sup>\u00a03d<sup>2<\/sup>\u00a04s<sup>2<\/sup>, and the element name is Titanium (T <sub>i<\/sub>).<br \/>(iii) n = 6<br \/>\u201d Means the element belongs to 6th period. Last electron goes to the f-orbital, element is from f-block.<br \/>group = 3<br \/>The element is gadolinium (z = 64)<br \/>Complete electronic configuration =[X<sub>e<\/sub>] 4 f<sup>7<\/sup>\u00a05d<sup>1<\/sup>\u00a06s<sup>2<\/sup>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-31-which-of-the-above-elements-is-likely-to-be-a-the-least-reactive-element-b-the-most-reactive-metal-c-the-most-reactive-non-metal-d-the-least-reactive-non-metal-e-the-metal-which-can-form-a-stable-binary-halide-of-the-formula-mx2x-halogen-f-the-metal-which-can-form-a-predominantly-stable-covalent-halide-of-the-formula-mx-x-halogen\"><\/span><strong>Question 31.<\/strong><br \/><img src=\"https:\/\/c2.staticflickr.com\/8\/7632\/27399498813_b9547d5274_o.png\" alt=\"ncert-solutions-for-class-11-chemistry-chapter-3-classification-of-elements-and-periodicity-in-properties-2\" width=\"676\" height=\"123\" \/><br \/><img src=\"https:\/\/c2.staticflickr.com\/8\/7121\/27935351461_05cfe2be3a_o.png\" alt=\"ncert-solutions-for-class-11-chemistry-chapter-3-classification-of-elements-and-periodicity-in-properties-3\" width=\"548\" height=\"106\" \/><br \/><strong>Which of the above elements is likely to be:<\/strong><br \/><strong>(a) the least reactive element (b) the most reactive metal<\/strong><br \/><strong>(c) the most reactive non-metal (d) the least reactive non-metal<\/strong><br \/><strong>(e) the metal which can form a stable binary halide of the formula MX<sub>2<\/sub>(X = halogen)<\/strong><br \/><strong>(f) the metal which can form a predominantly stable covalent halide of the formula MX (X = halogen)?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>(a) The element V has highest first ionization enthalpy (\u2206\u00a0<sub>i<\/sub>H<sub>1<\/sub>) and positive electron gain enthalpy (\u2206<sub>eg <\/sub>H) and hence it is the least reactive element. Since inert gases have positive <sub>eg <\/sub>H, therefore, the element-V must be an inert gas. The values of \u2206\u00a0<sub>i\u00a0<\/sub>H<sub>1<\/sub>,\u00a0\u2206\u00a0<sub>i<\/sub>H<sub>2<\/sub>\u00a0and \u2206<sub>eg <\/sub>H match that of He.<\/p>\n<p>(b) The element II which has the least first ionization enthalpy (\u2206\u00a0<sub>i\u00a0<\/sub>H<sub>1<\/sub>) and a low negative electron gain enthalpy (\u2206<span style=\"font-size: 15.8333px\">eg <\/span>H) is the most reactive metal. The values of \u2206\u00a0<sub>i\u00a0<\/sub>H<sub>1<\/sub>,\u00a0\u2206\u00a0<sub>i<\/sub>H<sub>2<\/sub> and \u2206<sub>eg <\/sub>H match that of K (potassium).<\/p>\n<p>(c) The element III which has high first ionization enthalpy (\u2206\u00a0<sub>i<\/sub>H<sub>1<\/sub>) and a very high negative electron gain enthalpy (\u2206<sub>eg <\/sub>H) is the most reactive non-metal. The values of \u2206\u00a0<sub>i\u00a0<\/sub>H<sub>1<\/sub>,\u00a0\u2206\u00a0<sub>i<\/sub>H<sub>2<\/sub>\u00a0and \u2206<sub>eg <\/sub>H match that of F (fluorine).<\/p>\n<p>(d) The element IV has a high negative electron gain enthalpy (\u2206<sub>eg <\/sub>H ) but not so high first ionization enthalpy (\u2206<sub>eg <\/sub>H). Therefore, it is the least reactive non-metal. The values of \u2206\u00a0<sub>i\u00a0<\/sub>H<sub>1<\/sub>,\u00a0\u2206\u00a0<sub>i<\/sub>H<sub>2<\/sub>\u00a0and \u2206<sub>eg <\/sub>H match that of I (Iodine).<\/p>\n<p>(e) The element VI has low first ionization enthalpy (\u2206\u00a0<sub>i<\/sub>H<sub>1<\/sub>) but higher than that of alkali metals. Therefore, it appears that the element is an alkaline earth metal and hence will form binary halide of the formula\u00a0MX<sub>2<\/sub>(where X = halogen). The values of \u2206\u00a0<sub>i\u00a0<\/sub>H<sub>1<\/sub>,\u00a0\u2206\u00a0<sub>i<\/sub>H<sub>2<\/sub>\u00a0and \u2206<sub>eg <\/sub>H match that of Mg (magnesium).<\/p>\n<p>(f) The element I has low first ionization (\u2206\u00a0<sub>i<\/sub>H<sub>1<\/sub>) but a very high second ionization enthalpy (\u2206\u00a0<sub>i<\/sub>H<sub>2<\/sub>), therefore, it must be an alkali metal. Since the metal forms a predominarly stable covalent halide of the formula MX (X = halogen), therefore, the alkali metal must be least reactive. The values of \u2206\u00a0<sub>i\u00a0<\/sub>H<sub>1<\/sub>,\u00a0\u2206\u00a0<sub>i<\/sub>H<sub>2<\/sub>\u00a0and \u2206<sub>eg <\/sub>H match that of Li (lithium).<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-32-predict-the-formulas-of-the-stable-binary-compounds-that-would-be-formed-by-the-combination-of-the-following-pairs-of-elements-a-lithium-and-oxygenb-magnesium-and-nitrogen-c-aluminium-and-iodined-silicon-and-oxygen-e-phosphorous-pentafluoride-f-element-71-and-fluorine\"><\/span><strong>Question 32. Predict the formulas of the stable binary compounds that would be formed by the combination\u00a0<\/strong><strong>of the following pairs of elements:<\/strong><br \/><strong>(a) Lithium and oxygen(b) Magnesium and nitrogen<\/strong><br \/><strong>(c) Aluminium and iodine(d) Silicon and oxygen<\/strong><br \/><strong>(e) Phosphorous pentafluoride (f) Element 71 and fluorine.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>\u00a0(a) Li0<sub>2<\/sub>(Lithium oxide)\u00a0(b)\u00a0Mg<sub>3<\/sub>N<sub>2<\/sub>(Magnesium nitride)<br \/>(c) AlI<sub>3<\/sub>(Aluminium iodide)\u00a0(d)\u00a0Si0<sub>2\u00a0<\/sub>(Silicon dioxide)<br \/>(e) Phosphorous and fluorine\u00a0(f) Z = 71<br \/>The element is Lutenium (Lu). Electronic configuration[X<sub>e<\/sub>] 4 f<sup>7<\/sup>\u00a05d<sup>1<\/sup>\u00a06s<sup>2<\/sup>.with\u00a0fluorine it will form a binary compound = Lu F3.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-33-in-the-modem-periodic-table-the-period-indicates-the-value-of-aatomic-number-b-mass-number-c-principal-quantum-number-d-azimuthal-quantum-number\"><\/span><strong>Question 33. In the modem periodic table, the period indicates the value of<\/strong><br \/><strong>(a)atomic number (b) mass number (c) principal quantum number (d) azimuthal quantum number?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0In the modern periodic table, each period begins with the filling of a new shell. Therefore, the period indicates the value of principal quantum number. Thus, option (c) is correct.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-34-which-of-the-following-statements-related-to-the-modem-periodic-table-is-incorrect-a-the-p-block-has-six-columns-because-a-maximum-of-6-electrons-can-occupy-all-the-orbitals-in-a-p-subshell\"><\/span><strong>Question 34. Which of the following statements related to the modem periodic table is incorrect?<\/strong><br \/><strong>(a) The p-block has six columns, because a maximum of 6 electrons can occupy all the orbitals in a p-subshell.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"b-the-d-block-has-8-columns-because-a-maximum-of-8-electrons-can-occupy-all-the-orbitals-in-a-d-subshell\"><\/span><strong>(b) The d-block has 8 columns, because a maximum of 8 electrons can occupy all the orbitals in a d-subshell.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"c-each-block-contains-a-number-of-columns-equal-to-the-number-of-electrons-that-can-occupy-that-subshell\"><\/span><strong>(c) Each block contains a number of columns equal to the number of electrons that can occupy that subshell.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"d-the-block-indicates-value-of-azimuthal-quantum-number-lfor-the-last-subshell-that-received-electrons-in-building-up-the-electronic-configuration\"><\/span><strong>(d) The block indicates value of azimuthal quantum number (l)for the last subshell that received electrons in building up the electronic configuration.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Statement (b) is incorrect.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-35-anything-that-influences-the-valence-electrons-will-affect-the-chemistry-of-the-element-which-one-of-the-following-factors-does-not-affect-the-valence-shell-a-valence-principal-quantum-number-n-b-nuclear-charge-z-c-nuclear-mass-d-number-of-core-electrons\"><\/span><strong>Question 35. Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell?<\/strong><br \/><strong>(a) Valence principal quantum number (n)<\/strong><br \/><strong>(b) Nuclear charge (Z)<\/strong><br \/><strong>(c) Nuclear mass<\/strong><br \/><strong>(d) Number of core electrons.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(c) Nuclear mass.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-36-the-size-of-isoelectronic-species-f%e2%80%93-ne-and-na-is-affected-by-a-nuclear-charge-z-b-valence-principal-quantum-number-n-c-electron-electron-interaction-in-the-outer-orbitals-d-none-of-the-factors-because-their-size-is-the-same\"><\/span><strong>Question 36. The size of isoelectronic species-F<sup>\u2013<\/sup>, Ne and\u00a0Na<sup>+\u00a0<\/sup>is affected by<\/strong><br \/><strong>(a) nuclear charge (Z)<\/strong><br \/><strong>(b) valence principal quantum number (n)<\/strong><br \/><strong>(c) electron-electron interaction in the outer orbitals<\/strong><br \/><strong>(d) none of the factors because their size is the same<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(a) Nuclear charge (Z).<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-37-which-of-the-following-statements-is-incorrect-in-relation-to-ionization-enthalpy-aionization-enthalpy-increases-for-each-successive-electron\"><\/span><strong>Question 37. Which of the following statements is incorrect in relation to ionization enthalpy?<\/strong><br \/><strong>(a)ionization enthalpy increases for each successive electron.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"bthe-greatest-increase-in-ionization-enthalpy-is-experienced-on-removal-of-electrons-from-core-noble-gas-configuration\"><\/span><strong>(b)The greatest increase in ionization enthalpy is experienced on removal of electrons from core noble gas configuration.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"cend-of-valence-electrons-is-marked-by-a-big-jump-in-ionization-enthalpy\"><\/span><strong>(c)End of valence electrons is marked by a big jump in ionization enthalpy.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"dremoval-of-electron-from-orbitals-bearing-lower-n-value-is-easier-than-from-orbital-having-higher-n-value\"><\/span><strong>(d)Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(d) is incorrect.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-38-considering-the-elements-b-al-mg-and-k-the-correct-order-of-their-metallic-character-is-a-b%3e-al%3e-mg-%3e-kb-al%3e-mg-%3e-b%3e-k-c-mg-%3e-al%3e-k%3e-b-d-k%3e-mg-%3e-al%3e-b\"><\/span><strong>Question 38. Considering the elements B, Al, Mg and K, the correct order of their metallic character is:<\/strong><strong>(a) B&gt; Al&gt; Mg &gt; K(b) Al&gt; Mg &gt; B&gt; K (c) Mg &gt; Al&gt; K&gt; B (d) K&gt; Mg &gt; Al&gt; B<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0In a period, metallic character decreases as we move from left to right. Therefore, metallic character of K, Mg and Al decreases in the order: K &gt; Mg &gt; Al. However, within a group, the metallic character, increases from top to bottom.<\/p>\n<p>Thus, Al is more metallic than B. Therefore, the correct sequence of decreasing metallic character is: K &gt; Mg &gt; Al &gt; B, i.e., option (d) is correct.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-39-considering-the-elements-b-c-n-f-and-si-the-correct-order-of-their-non-metallic-character-is-a-b%3ec%3esi%3en%3ef-b-si%3ec%3eb%3en%3ef-c-f%3en%3ec%3eb%3esi-d-f%3en%3ec%3esi%3eb\"><\/span><strong>Question 39. Considering the elements B, C, N, F and Si, the correct order of their non-metallic character is: (a) B&gt;C&gt;Si&gt;N&gt;F (b) Si&gt;C&gt;B&gt;N&gt;F (c) F&gt;N&gt;C&gt;B&gt;Si (d) F&gt;N&gt;C&gt;Si&gt;B<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0In a period, the non-metallic character increases from left to right. Thus, among B, C, N and F, non-metallic character decreases in the order: F &gt; N &gt; C &gt; B. However, within a group, non-metallic character decreases from top to bottom.<\/p>\n<p>Thus, C is more non-metallic than Si. Therefore, the correct sequence of decreasing non-metallic character is: F &gt; N &gt; C &gt; B &gt; Si, i.e., option (c) is correct.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-40-considering-the-elements-f-cl-o-and-n-the-correct-order-of-their-chemical-reactivity-in-terms-of-oxidising-property-is-a-f-%3e-cl%3e-o-%3e-n-b-f-%3e-o-%3e-cl%3e-n-c-cl%3e-f-%3e-o-%3e-n-d-o-%3e-f-%3e-n-%3e-cl\"><\/span><strong>Question 40. Considering the elements F, Cl, O and N, the correct order of their chemical reactivity in terms of oxidising property is:<\/strong><br \/><strong>(a) F &gt; Cl&gt; O &gt; N (b) F &gt; O &gt; Cl&gt; N (c) Cl&gt; F &gt; O &gt; N (d) O &gt; F &gt; N &gt; Cl<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Within a period, the oxidising character increases from left to right. Therefore, among F, O and N, oxidising power decreases in the order: F &gt; O &gt; N. However, within a group, oxidising power decreases from top to bottom. Thus, F is a stronger oxidising agent than Cl.<\/p>\n<p>Further because O is more electronegative than Cl, therefore, O is a stronger oxidising agent than Cl. Thus, overall decreasing order of oxidising power is: F &gt; O &gt; Cl &gt; N, i.e., option (b) is correct.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"more-questions-solved\"><\/span><strong>MORE QUESTIONS SOLVED<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span style=\"background-color: initial\"><b>I. Very<\/b><\/span><strong>\u00a0Short Answer Type Questions<\/strong><\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-1-state-the-modem-periodic-law\"><\/span><strong>Question 1. State the Modem Periodic Law.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Modem Periodic Law states that physical and chemical properties of the elements are a periodic function of their atomic numbers.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-2-why-is-ionization-enthalpy-of-nitrogen-greater-than-that-of-oxygen\"><\/span><strong>Question 2. Why is ionization enthalpy of nitrogen greater than that of oxygen?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Nitrogen has exactly half filled p-orbitals.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-3-why-are-electron-gain-enthalpies-of-be-and-mg-positive\"><\/span><strong>Question 3. Why are electron gain enthalpies of Be and Mg positive?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0They have fully filled s-orbitals and hence have no tendency to accept an additional electron. That\u2019s why energy is needed if an extra electron is to be added. Therefore, electron gain enthalpies of Be and Mg are positive.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-4-give-four-examples-of-species-which-are-isoelectronic-with-ca2\"><\/span><strong>Question 4. Give four examples of species which are isoelectronic with\u00a0ca<sup>2+<\/sup>.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>Ar, K<sup>+<\/sup>, CT, S<sup>2-<\/sup>, or\u00a0P<sup>3-\u00a0<\/sup>are isoelectronic with\u00a0ca<sup>2+<\/sup>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-5-which-two-elements-of-the-following-belong-to-the-same-period-al-si-ba-and-o\"><\/span><strong>Question 5. Which two elements of the following belong to the same period?<\/strong><br \/><strong>Al, Si, Ba and O<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Al and Si.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-6-explain-why-chlorine-can-be-converted-into-chloride-ion-more-easily-as-compared-to-fluoride-ion-from-fluorine\"><\/span><strong>Question 6. Explain why chlorine can be converted into chloride ion more easily as compared to fluoride ion from fluorine ?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Electron gain enthalpy of Cl is more negative than that of F.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-7-what-are-horizontal-rows-and-vertical-columns-of-the-periodic-table-called\"><\/span><strong>Question 7. What are horizontal rows and vertical columns of the periodic table called?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Horizontal rows are called periods and vertical columns are called groups.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-8-which-has-a-larger-radius-img-or-ca-ii-s-or-cl\"><\/span><strong>Question 8. Which has a larger radius?<\/strong><br \/><strong>(i)Mg or Ca (ii) S or Cl<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(i) Ca (ii) S.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-9-what-are-representative-elements\"><\/span><strong>Question 9. What are representative elements?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0The elements of group 1 (alkali metals), group 2,(alkaline earth metals) and group 13 to 17 constitute the representative elements. They are elements of s-block and p-block.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-10-give-general-electronic-configuration-off-block-elements\"><\/span><strong>Question 10. Give general electronic configuration off-block elements?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0General electronic configuration of f-block elements =(n \u2013 2) f<sup>1-14\u00a0<\/sup>(n -1) d<sup>0-1\u00a0<\/sup>ns<sup>2<\/sup>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-11-what-are-inner-transition-metals-why-are-they-called-rare-earth-metals\"><\/span><strong>Question 11. What are inner transition metals? Why are they called rare earth metals?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Lanthanoids (the fourteen elements after Lanthanum) and actinides (the fourteen elements after actinium) are called inner transition elements.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-12-define-ionisation-enthalpy\"><\/span><strong>Question 12. Define ionisation enthalpy.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0It is the energy required to remove an electron from an isolated gaseous atom in its ground state. M (g) + I.E. \u00e0M<sup>+<\/sup>\u00a0(g) + e<sup>\u2013<\/sup><\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-13-the-electronic-configuration-of-an-element-is-is-2s-2p-3s-3p-4s-locate-the-element-in-the-periodic-table\"><\/span><strong>Question 13. The electronic configuration of an element is Is 2s 2p 3s 3p 4s . Locate the element in the periodic table.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0<\/p>\n<ul>\n<li>As the principal quantum number for the valence shell is 4, the element is present in the 4th period.<\/li>\n<li>Since the last electron has been filled in 4s sub-shell (or orbital), the element belongs to s-block.<\/li>\n<li>As there is only one electron in the valence s-sub-shell, the element is present in group I.<\/li>\n<\/ul>\n<p><strong>II. Short Answer Type Questions<\/strong><\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-1-what-is-the-cause-of-periodicity-in-properties-of-the-elements-explain-with-two-examples\"><\/span><strong>Question 1. What is the cause of periodicity in properties of the elements? Explain with two examples.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0The cause of periodicity in properties is the repetition of similar outer electronic configuration after certain regular intervals.<br \/>For example, all the elements of group LA i.e., alkali metals, have similar outer electronic configuration as ns<sup>1<\/sup>.<\/p>\n<p>Where n refer to the number of outermost principal shell.<br \/>In a similar manner all the halogens i.e., elements of group VILA have similar other electronic configuration i.e., ns<sup>2<\/sup>\u00a0ns<sup>5<\/sup>\u00a0and hence possess similar properties.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-2-show-by-a-chemical-reaction-with-water-that-na20-is-a-basic-oxide-and-cl207-is-an-acidic-oxide\"><\/span><strong>Question 2. Show by a chemical reaction with water that Na<sub>2<\/sub>0 is a basic oxide and\u00a0Cl<sub>2<\/sub>0<sub>7<\/sub>\u00a0is an acidic oxide.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Na<sub>2\u00a0<\/sub>0reacts with water to form sodium oxide which turns red litmus blue.<br \/>Na<sub>2<\/sub>0 +H<sub>2<\/sub>0\u2014\u2014-&gt; 2NaOH<br \/>Sod.oxide Sod.hydroxide<br \/>Therefore, Na20 is a basic oxide<br \/>In contrast,Cl<sub>2<\/sub>0<sub>7<\/sub>\u00a0reacts with water to form perchloric acid which turns blue litmus red.<br \/>Cl<sub>2<\/sub>0<sub>7<\/sub>\u00a0+H<sub>2<\/sub>0\u2014\u2014\u2013&gt;2HClO<sub>4<\/sub><br \/>perchloric acid<br \/>Therefore, Cl<sub>2<\/sub>0<sub>7<\/sub>\u00a0is an acidic oxide.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-3-what-do-you-understand-by-%e2%80%98representative-elements%e2%80%99-name-the-groups-whose-elements-are-called-representative-elements\"><\/span><strong>Question 3. What do you understand by \u2018Representative elements\u2019? Name the groups whose elements are called representative elements.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0The elements of s and p-block are collectively called representative or main group elements. These include elements of group I (alkali metals), group 2 (alkaline earth metals). .<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-4-name-different-blocks-of-elements-in-the-periodic-table-give-general-electronic-configuration-of-each-block\"><\/span><strong>Question 4. Name different blocks of elements in the periodic table. Give general electronic configuration of each block.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Elements in the long form of the periodic table have been divided into four blocks i.e., s, p, d and f. This division is based upon the name of the orbital which receives the last electron.<\/p>\n<p>General electronic configuration of s-block elements:\u00a0ns<sup>1 \u2013 2\u00a0<\/sup>where n = 2 \u2013 7<br \/>p-block elements:\u00a0ns<sup>2<\/sup>\u00a0np<sup>1- 6\u00a0<\/sup>where n = 2 \u2013 6<br \/>d-block elements: (n -1)\u00a0d<sup>1 -10<\/sup>\u00a0ns<sup>0- 2\u00a0<\/sup>where n = 4 \u2013 7<br \/>f-block elements: (n \u2013 2)f<sup>0-14<\/sup>(n -1)\u00a0d<sup>0-1\u00a0<\/sup>ns<sup>2\u00a0<\/sup>where n = 6 \u2013 7<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-5-elements-a-b-c-and-d-iwoe-atomic-numbers-1219-29-and-36-respectively-on-the-basis-of-electronic-configuration-write-to-which-group-of-the-periodic-table-each-element-belongs\"><\/span><strong>Question 5. Elements A, B, C and D Iwoe atomic numbers 12,19, 29, and 36 respectively. On the basis of\u00a0<\/strong><strong>electronic configuration, write to which group of the periodic table each element belongs.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Electronic configuration of A (Z = 12)<br \/>=1s<sup>2\u00a0<\/sup>2s<sup>2<\/sup>\u00a02p<sup>6<\/sup>\u00a03s<sup>2<\/sup><br \/>period = 3, Element\u2019s name = Mg block = s, Group = II Electronic configuration of B (Z = 19)<br \/>Element\u2019s name = K (potassium)<br \/>=1s<sup>2<\/sup>\u00a02s<sup>2<\/sup>\u00a02p<sup>6<\/sup>\u00a03s<sup>2<\/sup>\u00a03p<sup>6<\/sup>\u00a04s<sup>1<\/sup> n = 4, period = 4 Block = s, Group = I Electronic configuration of C (Z = 29)<br \/>=1s<sup>2<\/sup>\u00a02s<sup>2<\/sup>\u00a02p<sup>6<\/sup>\u00a03s<sup>2<\/sup>\u00a03p<sup>6<\/sup>\u00a03d<sup>10<\/sup>\u00a04s<sup>1\u00a0<\/sup>n \u2013 4, period = 4 Block = d\u00a0Electronic configuration of D (Z = 36)<br \/>=1s<sup>2\u00a0<\/sup>2s<sup>2<\/sup>\u00a02p<sup>6<\/sup>\u00a03s<sup>2<\/sup>\u00a03p<sup>6<\/sup>\u00a04s<sup>2<\/sup>\u00a03d<sup>10<\/sup>\u00a04p<sup>6\u00a0<\/sup>period = 4 Block = p-Block group = 18<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-6-define-the-term-ionization-enthalpy-how-does-it-vary-along-a-period-and-along-a-group\"><\/span><strong>Question 6. Define the term ionization enthalpy? How does it vary along a period and along a group?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0Ionization Enthalpy. The minimum amount of energy required to remove the most loosely bound electron from an isolated gaseous atom so as to convert it into a gaseous cation is called its ionization enthalpy or energy. It is represented by A; H.<\/p>\n<p>This process may be represented as\u00a0M (g) + \u2206<sub>i<\/sub>H -&gt; M<sup>+<\/sup>\u00a0(g) + e<sup>\u2013<\/sup>(g)<br \/>where M (g) is isolated gaseous atom.<br \/>M<sup>+<\/sup>\u00a0(g) is the resultant cation (a position ion)<br \/><strong>Variation along a period.<\/strong>\u00a0Moving from left to right in a period, the ionization enthalpy increases with atomic number.<br \/><strong>Variation within a group.<\/strong>\u00a0The ionization enthalpies keep on decreasing regularly as we move down a group from one element to the other.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-7-discuss-briefly-the-various-factors-on-which-ionization-enthalpy-depends\"><\/span><strong>Question 7. Discuss briefly the various factors on which ionization enthalpy depends.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong><\/p>\n<ol>\n<li><strong>Atomic size.<\/strong>\u00a0With the increase in the atomic size, the number of electron shells<br \/>increases. Therefore, the force that binds the electrons with the nucleus decreases. Thus, the ionization enthalpy decreases with increase in atomic size.<\/li>\n<li><strong>\u00a0Nuclear charge.<\/strong>\u00a0As the magnitude of the positive charge on the nucleus of an atom increases, the attraction with the electrons also increases. Therefore, the ionization enthalpy increases with the increase in the magnitude of the nuclear charge.<\/li>\n<li><strong>\u00a0Screening or shielding effect.<\/strong>\u00a0Greater the magnitude of the screening effect, less will be the value of ionization enthalpy or potential.<\/li>\n<\/ol>\n<h3><span class=\"ez-toc-section\" id=\"question-8-what-are-dobereiner-triads-name-two-such-triads\"><\/span><b>Question 8. What are Dobereiner triads? Name two such triads.<\/b><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong> Dobereiner arranged certain elements with similar properties in groups of three in such a way that the atomic mass of the middle element was nearly the same as the average atomic masses of the first and third elements.<\/p>\n<p>For example:<br \/>Triad: lithium sodium potassium<br \/>Atomic mass: 7 23 39<br \/>Atomic mass of Na =(39+7)\/2= 23<br \/>Triad: Chlorine Bromine Iodine<br \/>Atomic mass: 35.5 80 127<br \/>Atomic mass of Br =127 + 35.5\/2 = 81.25<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-9-give-the-electronic-configuration-of-the-transition-elements-write-their-four-important-characteristics\"><\/span><strong>Question 9. Give the electronic configuration of the transition elements. Write their four important characteristics.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0The d-block elements are known as transition elements.<br \/>Electronic configuration =(n \u2013 1) d<sup>1-10\u00a0<\/sup>ns<sup>1 -2<\/sup><br \/><strong>Characteristics of d-block elements:<\/strong><\/p>\n<ul>\n<li>They show variable oxidation states.<\/li>\n<li>Their compounds are generally paramagnetic in nature.<\/li>\n<li>Most of the transition elements form coloured compounds.<\/li>\n<li>They are all metals with high melting and boiling points.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"question-10-what-is-screening-or-shielding-effect-how-does-it-influence-the-ionization-enthalpy\"><\/span><strong>Question 10. What is screening or shielding effect? How does it influence the ionization enthalpy ?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0In a multielectron atom, the electrons present in the inner shells shield the electrons in the valence shell from the attraction of the nucleus or they act as a screen between the nucleus and these electrons.<\/p>\n<p>This is known as shedding effect or screening effect. As the screening effect increases, the effective nuclear charge decreases. Consequently, the force of attraction by the nucleus for the valence shell electrons decreases and hence the ionization enthalpy decreases.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-11-define-electron-gain-enthalpy-what-are-its-units\"><\/span><strong>Question 11. Define electron gain enthalpy. What are its units?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>\u00a0The energy which is released by an atom in gaining an electron from outside atom or ion to form negative ion (or anion) is called electron gain enthalpy (\u2206<sub>eg <\/sub>H).<br \/>Unit of electron gain enthalpy is kJ\/ mol.<br \/>In some cases, like in noble gas, atoms do not have any attraction to gain an electron. In that case energy has to be supplied.<br \/>For example,<br \/>Ne (g) + e<sup>\u2013<\/sup>\u00a0\u2014&gt; Ne<sup>\u2013\u00a0<\/sup>(g)<br \/>\u2206<sub>eg <\/sub>H = + 116 kJ mol\u00a0<sup>-1<\/sup><\/p>\n<p><strong>III. Long Answer Type Questions<\/strong><\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-1-discuss-the-main-features-of-long-form-of-the-periodic-table-what-are-the-advantages-of-long-form-of-periodic-table\"><\/span><strong>Question 1. Discuss the main features of long form of the periodic table. What are the advantages of long . form of periodic table?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0<strong>Main features of long form of periodic table:<\/strong><\/p>\n<ul>\n<li><strong>Groups.<\/strong>\u00a0The vertical columns in the periodic table are known as groups. There are 18 groups in the long form of periodic table.<br \/>Each group having the same electronic configuration in the outermost shell.<\/li>\n<li><strong>Periods.<\/strong>\u00a0There are 7 periods in the long form of periodic table.<br \/>It is denoted by n which means highest principal quantum number.<\/li>\n<li><strong>Lanthanoids.<\/strong>\u00a0Group of 14 elements in the sixth period. They are placed after Lanthanum.<\/li>\n<li><strong>Actinides.<\/strong>\u00a0Group of 14 elements in the seventh period after actinium. Both Lanthanoids and actinoids are placed in separate panel at the bottom of the periodic table.<\/li>\n<\/ul>\n<p><strong>Advantages of long form of periodic table:<\/strong><\/p>\n<ul>\n<li>It gives a suitable link between the position of element and its electronic\u00a0configuration.<\/li>\n<li>On the basis of atomic numbers it easier to remember all the elements.<\/li>\n<li>The elements in the same group have similar properties due to their outer-most (valence shell) configuration. Thus it gives is a logical classification.<\/li>\n<li>Justified positions are provided to transition and inner transition elements. \u2018<\/li>\n<li>\u00a0It makes the study of elements systematic and simple.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"question-2-discuss-the-main-characteristics-of-four-blocks-of-elements-in-the-periodic-table-give-their-general-electronic-configuration\"><\/span><strong>Question 2. Discuss the main characteristics of four blocks of elements in the periodic table? Give their general electronic configuration.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer: s-block elements:<\/strong><\/p>\n<ul>\n<li>They are highly reactive elements and thus occurs in combined state. On moving down the group their reactivity increases.<\/li>\n<li>They have good reducing characters.<\/li>\n<li>They generally form electropositive ion by losing 1 or 2 electrons, that\u2019s why they are electro positive in nature.<\/li>\n<li>They are good conductors of heat and electricity.<\/li>\n<\/ul>\n<p><strong>p-block elements:<\/strong><\/p>\n<ul>\n<li>Most of the p-block elements show variable oxidation states.<\/li>\n<li>They include both metals and non-metals.<\/li>\n<li>They are generally covalent in nature.<\/li>\n<li>As move from left to right the non-metallic character of the element increases.<\/li>\n<li>On moving down the group metallic character increases.<\/li>\n<\/ul>\n<p><strong>d-block elements:<\/strong><\/p>\n<ul>\n<li>d-block elements show variable oxidation states.<\/li>\n<li>\u00a0They are generally paramagnetic in nature.<\/li>\n<li>Their compounds are generally coloured. Those which form complex compounds.<\/li>\n<li>Most of the elements and their compounds acts as catalyst.<\/li>\n<\/ul>\n<p><strong>f-block elements:<\/strong><\/p>\n<ul>\n<li>They are generally heavy metals having high melting and boiling points.<\/li>\n<li>Their compounds are generally coloured.<\/li>\n<li>Variable oxidation states are generally shown by these elements.<\/li>\n<li>Most of Activities are radioactive.<\/li>\n<\/ul>\n<p><strong>General electronic configuration:<\/strong><br \/>s-block \u2014ns<sup>1-2<\/sup><br \/>p-block \u2014ns<sup>2<\/sup>\u00a0np<sup>1- 6<\/sup><br \/>d-block \u2014(n -1) d<sup>1 -10\u00a0<\/sup>ns<sup>0-2<\/sup><br \/>f-block \u2014(n \u2013 2)f<sup>0-14<\/sup>\u00a0(n -1) d<sup>0- 1\u00a0<\/sup>ns<sup>2<\/sup><\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-3-define-electron-gain-enthalpy-what-are-its-units-discuss-the-factors-which-influence-the-electron-gain-enthalpy\"><\/span><strong>Question 3. Define electron gain enthalpy. What are its units? Discuss the factors which influence the electron gain enthalpy.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>\u00a0Electron gain enthalpy is the energy released when an isolated gaseous atom is converted into a negative ion by adding an extra electron.<br \/>Electron gain enthalpy is denoted by the sign \u2206<sub>eg <\/sub>H.<br \/>The process may be represented by<br \/>M(g) + e<sup>\u2013<\/sup>\u00a0\u2014\u2014\u2014\u2014\u2014\u2014\u2014&gt;M<sup>\u2013<\/sup>\u00a0(g)<br \/>neutral gaseous\u00a0atom anion<br \/>\u2206 H<sub>=<\/sub>\u2206<sub>eg\u00a0<\/sub>H<br \/>electron gain enthalpy is negative or positive it depends upon the nature of the element. For example. For halogens it is highly negative, because they can acquire the noble gas configuration by accepting an extra electron.<\/p>\n<p><strong>In contrast.<\/strong>\u00a0For noble gases have positive electron gain enthalpy because energy has to be supplied to the element.<br \/><strong>Factors on which electron gain enthalpy depends:<\/strong><\/p>\n<ol>\n<li><strong>Atomic size.<\/strong>\u00a0As the size of an atom increases, the distance between its nucleus and the incoming electron also increases.<\/li>\n<li>Therefore, the force of attraction between the nucleus and the incoming electron decreases and hence the electron gain enthalpy becomes less negative.<\/li>\n<li><strong>Nuclear charge.<\/strong>\u00a0As the nuclear charge increases force of attraction for the incoming electron increases and thus electron gain enthalpy becomes more negative.<\/li>\n<li><strong>Symmetry of electronic configuration.<\/strong> Elements having symmetrical configuration (Either half filled or fully filled orbitals in the same sub shell) having no attraction for electron because by accepting electron their configuration becomes less stable.<\/li>\n<li>In that case energy has to be supplied to accept electron. Thus electron gain enthalpy will be positive.<\/li>\n<\/ol>\n<h3><span class=\"ez-toc-section\" id=\"question-4-discuss-the-factors-that-influence-the-magnitude-of-ionization-enthalpy-what-are-the-general-trends-of-variation-of-ionization-enthalpy-in-the-periodic-table-explain\"><\/span><strong>Question 4. Discuss the factors that influence the magnitude of ionization enthalpy. What are the general trends of variation of ionization enthalpy in the periodic table? Explain.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0Factors affecting Ionization enthalpy.<\/strong><\/p>\n<ol>\n<li><strong>Atomic size.<\/strong>\u00a0With the increase in atomic size, the number of electron shells increases and thus the force of attraction between the electrons and the nucleus decreases. Therefore the ionization enthalpy decreases.<\/li>\n<li><strong>Nuclear charge.<\/strong>\u00a0As the nuclear charge increases the attraction for the electron also increases that\u2019s why ionization enthalpy increases.<\/li>\n<li><strong>Screening or shielding effect.<\/strong>\u00a0In a multi-electron atom, the electron present in the inner shells shield the electrons in the valence shell as a result these electrons<br \/>experience less attraction from the nucleus.<\/li>\n<li>This leads to lesser ionization enthalpy.\n<ul>\n<li><strong>Variation along a period.<\/strong>\u00a0On moving from left to right in a period the nuclear charge increases and the atomic size decreases as a result ionization enthalpies are expected to increase.<\/li>\n<li><strong>Variation within a group.<\/strong>\u00a0On moving down the group as the atomic size of the elements increases that\u2019s why ionization enthalpy decreases down the group.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<h3><span class=\"ez-toc-section\" id=\"question-5-a-how-does-atomic-radius-vary-in-group-in-the-periodic-table-b-explain-i-radius-of-cation-is-less-than-that-of-the-atom-ii-radius-of-anion-is-more-than-that-of-the-atom-iii-in-iso-electronic-ion-the-ionic-radii-decreases-with-increase-in-atomic-number\"><\/span><strong>Question 5. (a) How does atomic radius vary in group in the periodic table?<\/strong><br \/><strong>(b) Explain<\/strong><br \/><strong>(i) Radius of cation is less than that of the atom.<\/strong><br \/><strong>(ii) Radius of anion is more than that of the atom.<\/strong><br \/><strong>(iii) In iso-electronic ion, the ionic radii decreases with increase in atomic number.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(a) Variation of atomic radius in a group:<br \/>On moving down the group there is an increase in the principal quantum number and therefore no. of electron shells increases and thus the atomic size increases. Thus the atomic radii of the element increases.<\/p>\n<p>(b) (i) Radius of cation is less than that of the atom:<br \/>Since the cation is formed by losing of one or more electrons.<br \/>For example,<br \/>Na \u2014&gt; Na<sup>+<\/sup>+ e<sup>\u2013<\/sup><br \/>Thus the radius of Na<sup>+ <\/sup>will be less than the Na.<br \/>(ii) Radius of anion is more than that of the atom.<br \/>Since the anion is formed by gaining one or more electron. Therefore, the atomic radius is larger than the corresponding atom.<br \/>(iii) In iso-electronic ions, atoms have same number of electrons but different magnitude of nuclear charges. As the nuclear charge increases ionic radius decreases.<br \/>For example.\u00a0N<sup>3-<\/sup>, O<sup>2-<\/sup>, F<sup>\u2013\u00a0<\/sup>have same No. of electrons = 10 but different ionic radii = 171,\u00a0140, 136 respectively.<\/p>\n<p><strong>IV. Multiple Choice Questions<\/strong><\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-1-the-highest-ionization-energy-is-exhibited-by-a-halogens-b-alkaline-earth-metals-c-transition-metals-d-noble-gases-question-2-which-of-the-following-oxides-is-neutral-a-sn02-b-co-c-al203-d-na20\"><\/span><strong>Question\u00a0<\/strong><strong>1. The highest ionization energy is exhibited by<\/strong><br \/><strong>(a) halogens (b) alkaline earth metals<\/strong><br \/><strong>(c) transition metals (d) noble gases<\/strong><br \/><strong>Question 2. Which of the following oxides is neutral?<\/strong><br \/><strong>(a) Sn0<sub>2<\/sub>\u00a0(b) CO (c) Al<sub>2<\/sub>0<sub>3<\/sub>\u00a0(d) Na<sub>2<\/sub>0<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"question-3-which-of-the-following-is-arranged-in-order-of-increasing-radius-a-k-aq-%3c-na-aq-%3c-li-aq-b-k-aq-%3e-na-aq-%3e-zn2-aq-c-k-aq-%3e-li-aq-%3e-na-aq-d-li-aq-%3c-na-aq-%3c-k-aq\"><\/span><strong>Question 3. Which of the following is arranged in order of increasing radius?<\/strong><br \/><strong>(a) K<sup>+<\/sup>\u00a0(aq) &lt; Na<sup>+<\/sup>\u00a0(aq) &lt; Li<sup>+<\/sup>\u00a0(aq) (b) K<sup>+<\/sup>\u00a0(aq) &gt; Na<sup>+<\/sup>\u00a0(aq) &gt; Zn<sup>2+<\/sup>\u00a0(aq)<\/strong><br \/><strong>(c) K<sup>+<\/sup>\u00a0(aq) &gt; Li<sup>+<\/sup>\u00a0(aq) &gt; Na<sup>+<\/sup>\u00a0(aq) (d) Li<sup>+<\/sup>\u00a0(aq) &lt; Na<sup>+<\/sup>\u00a0(aq) &lt; K<sup>+<\/sup>\u00a0(aq)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"question-4-what-is-the-electronic-configuration-of-the-elements-of-group-14-a-ns2-np4-b-ns2-np6-c-ns2-np2-d-ns2\"><\/span><strong>Question 4. What is the electronic configuration of the elements of group 14?<\/strong><br \/><strong>(a) ns<sup>2<\/sup>\u00a0np<sup>4<\/sup>\u00a0(b) ns<sup>2<\/sup>\u00a0np<sup>6<\/sup>\u00a0(c) ns<sup>2<\/sup>\u00a0np<sup>2\u00a0<\/sup>(d) ns<sup>2<\/sup><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"question-5-among-the-following-elements-which-has-the-least-electron-affinity-a-phosphorous-b-oxygen-c-sulphur-d-nitrogen\"><\/span><strong>Question 5. Among the following elements, which has the least electron affinity?<\/strong><br \/><strong>(a) Phosphorous (b) Oxygen (c) Sulphur (d) Nitrogen<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"question-6-in-halogens-which-of-the-following-increases-from-iodine-to-fluorine-a-bond-length-b-electronegativity-c-the-ionization-energy-of-the-element-d-oxidizing-power\"><\/span><strong>Question 6. In halogens, which of the following, increases from iodine to fluorine?<\/strong><br \/><strong>(a) Bond length (b) Electronegativity<\/strong><br \/><strong>(c) The ionization energy of the element (d) Oxidizing power<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"question-7-diagonal-relationships-are-shown-by-a-be-and-a1-b-mg-and-a1-c-li-and-mg-d-b-and-p\"><\/span><strong>Question 7. Diagonal relationships are shown by<\/strong><br \/><strong>(a) Be and A1 (b) Mg and A1 (c) Li and Mg (d) B and P<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"question-8-which-of-the-following-species-are-not-known-a-agoh-b-pbi4-c-pi5-d-sh6-e-all-of-the-above\"><\/span><strong>Question 8. Which of the following species are not known?<\/strong><br \/><strong>(a) AgOH (b) PbI<sub>4<\/sub>\u00a0(c) PI<sub>5<\/sub>\u00a0(d) SH<sub>6<\/sub><\/strong><br \/><strong>(e) All of the above<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"question-9-which-one-of-the-following-is-isoelectronic-with-ne-a-n3-b-mg2-c-al3-dall-of-the-above\"><\/span><strong>Question 9. Which one of the following is isoelectronic with Ne?<\/strong><br \/><strong>(a) N<sup>3-<\/sup>\u00a0(b) Mg<sup>2+<\/sup>\u00a0(c) Al<sup>3+<\/sup>\u00a0(d)all of the above<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"question-10which-element-has-smallest-size-a-b-b-n-c-al-d-p\"><\/span><strong>Question 10.Which element has smallest size?<\/strong><br \/><strong>(a) B (b) N (c) Al (d) P<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a01. (b) 2. (b) 3. (d) 4. (c) 5. (d)<br \/>6. (b) (c) and (d)7. (a) and (c)8. (e)9. (d) 10. (b)<\/p>\n<h3><span class=\"ez-toc-section\" id=\"v-hots-questions-question-1-arrange-the-following-as-stated-i-n2-02-f2-cl2increasing-order-of-bond-dissociation-energy-ii-f-cl-br-i-increasing-order-of-electron-gain-enthalpy-iii-f2-n2-cl2-o2increasing-order-of-bond-length\"><\/span><strong>V. Hots Questions<\/strong><br \/><strong>Question 1. Arrange the following as stated: (i) N<sub>2<\/sub>, 0<sub>2<\/sub>, F<sub>2<\/sub>, Cl<sub>2<\/sub>(Increasing order of bond dissociation energy) (ii) F, Cl, Br, I (Increasing order of electron gain enthalpy) (iii)\u00a0F<sub>2<\/sub>, N<sub>2<\/sub>, Cl<sub>2<\/sub>, O<sub>2<\/sub>(Increasing order of bond length).<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(i) F<sub>2<\/sub>\u00a0&lt; Cl<sub>2<\/sub>\u00a0&lt; 0<sub>2<\/sub>\u00a0&lt; N<sub>2<\/sub><br \/>(ii) I &lt; Br &lt; F &lt; Cl<br \/>(iii) N<sub>2<\/sub>\u00a0&lt; 0<sub>2<\/sub>\u00a0&lt; F<sub>2<\/sub>\u00a0&lt; Cl<sub>2<\/sub><\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-2-the-first-ionisation-enthalpy-of-magnesium-is-higher-than-that-of-sodium-on-the-other-hand-the-second-ionisation-enthalpy-of-sodium-is-very-much-higher-than-that-of-magnesium-explain\"><\/span><strong>Question 2. The first ionisation enthalpy of magnesium is higher than that of sodium. On the other hand, the second ionisation enthalpy of sodium is very much higher than that of magnesium. Explain.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:\u00a0<\/strong>\u00a0The 1st ionisation enthalpy of magnesium is higher than that of Na due to higher nuclear charge and slightly smaller atomic radius of Mg than Na.<\/p>\n<p>After the loss of first electron, Na<sup>+<\/sup> formed has the electronic configuration of neon (2, 8). The higher stability of the completely filled noble gas configuration leads to very high second ionisation enthalpy for sodium.<\/p>\n<p>On the other hand, Ma<sup>+<\/sup>\u00a0formed after losing first electron still has one more electron in its outermost (3s) orbital. As a result, the second ionisation enthalpy of magnesium is much smaller than that of sodium.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"question-3-give-reasons-i-ie1-of-sodium-is-lower-than-that-of-magnesium-whereas-ie2-of-sodium-is-higher-than-that-of-magnesium-ii-noble-gases-have-positive-value-of-electron-gain-enthalpy\"><\/span><strong>Question 3. Give reasons:<\/strong><br \/><strong>(i) IE<sub>1\u00a0<\/sub>of sodium is lower than that of magnesium whereas\u00a0IE<sub>2\u00a0<\/sub>of sodium is higher than that of magnesium.<\/strong><br \/><strong>(ii) Noble gases have positive value of electron gain enthalpy.<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Answer:<\/strong>\u00a0(i) The effective nuclear charge of magnesium is higher than that of sodium. For these reasons, the energy required to remove an electron from magnesium is more than the energy required in sodium. Hence, the first ionization enthalpy of sodium is lower than that of magnesium.<\/p>\n<p>However, the second ionization enthalpy of sodium is higher than that of magnesium.<br \/>This is because after losing an electron, sodium attains the stable noble gas configuration. On the other hand, magnesium, after losing on electron still has one electron.<br \/>(ii)Because of stable configuration.<\/p>\n<p>Here we presented you with everything about <a href=\"http:\/\/cbse.nic.in\/\" target=\"_blank\" rel=\"noopener\">CBSE<\/a> NCERT Solutions For Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties. Still, if you find any sort of doubts makes sure to ask us since are always here to help you out.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"faq-ncert-solutions-for-class-11-chemistry-chapter-3-classification-of-elements-and-periodicity-in-properties\"><\/span>FAQ: NCERT Solutions For Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n<div id=\"rank-math-faq\" class=\"rank-math-block\">\n<div class=\"rank-math-list \">\n<div id=\"faq-question-1627382275706\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \"><span class=\"ez-toc-section\" id=\"can-i-download-ncert-solutions-for-class-11-chemistry-chapter-3-for-free\"><\/span>Can I download NCERT Solutions For Class 11 Chemistry Chapter 3 for free? <span class=\"ez-toc-section-end\"><\/span><\/h3>\n<div class=\"rank-math-answer \">\n\n<p>Yes, you can download NCERT Solutions For Class 11 Chemistry Chapter 3 for free. <\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-question-1627382313608\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \"><span class=\"ez-toc-section\" id=\"what-is-the-name-of-chapter-3-in-chemistry-class-11\"><\/span>What is the name of Chapter 3 in chemistry class 11?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<div class=\"rank-math-answer \">\n\n<p>Classification of Elements and Periodicity in Properties\u00a0is the third chapter in the NCERT Solutions For Class 11 Chemistry Chapter 3 syllabus.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-question-1627382315233\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \"><span class=\"ez-toc-section\" id=\"what-are-the-topics-included-in-periodic-trends-in-properties-of-elements-of-ncert-solutions-for-class-11-chemistry-chapter-3\"><\/span>What are the topics included in Periodic Trends In Properties Of Elements of NCERT Solutions For Class 11 Chemistry Chapter 3? <span class=\"ez-toc-section-end\"><\/span><\/h3>\n<div class=\"rank-math-answer \">\n\n<p>Trends in Physical Properties<br \/>Periodic Trends In Chemical Properties<br \/>Periodic Trends And Chemical Reactivity<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-question-1627382318236\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \"><span class=\"ez-toc-section\" id=\"what-is-periodic-properties-ncert-solutions-for-class-11-chemistry-chapter-3\"><\/span>What is periodic properties NCERT Solutions For Class 11 Chemistry Chapter 3?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<div class=\"rank-math-answer \">\n\n<p>The basic law governing modern periodic table states that the properties of elements are\u00a0periodic functions of their atomic number. <br \/>These properties reappear at regular intervals or follow a particular trend at regular intervals. This phenomenon is known as the periodicity of elements.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-question-1627382319462\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \"><span class=\"ez-toc-section\" id=\"how-many-elements-are-present-now\"><\/span>How many elements are present now?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<div class=\"rank-math-answer \">\n\n<p>At present,\u00a0118 elements\u00a0are known to us.<\/p>\n\n<\/div>\n<\/div>\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>\u00a0 NCERT Solutions For Class 11 Chemistry Chapter 3: Getting ready with NCERT Solutions For Class 11 Chemistry Chapter 3 might seem easy at the beginning, however, it is not the case to be precise. Class 10 is just a pond compared to the syllabus prescribed in the 11th standard. And if you aspire for &#8230; <a title=\"Class 11 Chemistry Chapter 3 NCERT Solutions 2021 For Classification of Elements and Periodicity in Properties\" class=\"read-more\" href=\"https:\/\/www.kopykitab.com\/blog\/ncert-solutions-for-class-11-chemistry-chapter-3\/\" aria-label=\"More on Class 11 Chemistry Chapter 3 NCERT Solutions 2021 For Classification of Elements and Periodicity in Properties\">Read more<\/a><\/p>\n","protected":false},"author":249,"featured_media":109903,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":""},"categories":[2934,73713,73413],"tags":[76473,76237,76472],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.kopykitab.com\/blog\/wp-json\/wp\/v2\/posts\/55573"}],"collection":[{"href":"https:\/\/www.kopykitab.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.kopykitab.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.kopykitab.com\/blog\/wp-json\/wp\/v2\/users\/249"}],"replies":[{"embeddable":true,"href":"https:\/\/www.kopykitab.com\/blog\/wp-json\/wp\/v2\/comments?post=55573"}],"version-history":[{"count":4,"href":"https:\/\/www.kopykitab.com\/blog\/wp-json\/wp\/v2\/posts\/55573\/revisions"}],"predecessor-version":[{"id":120901,"href":"https:\/\/www.kopykitab.com\/blog\/wp-json\/wp\/v2\/posts\/55573\/revisions\/120901"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.kopykitab.com\/blog\/wp-json\/wp\/v2\/media\/109903"}],"wp:attachment":[{"href":"https:\/\/www.kopykitab.com\/blog\/wp-json\/wp\/v2\/media?parent=55573"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.kopykitab.com\/blog\/wp-json\/wp\/v2\/categories?post=55573"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.kopykitab.com\/blog\/wp-json\/wp\/v2\/tags?post=55573"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}