Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

Classification of Elements and Periodicity in Properties

Short Answer Type

111. Describe the theory associated with the radius of an atom as it gains on electron.

134 Views

112. Describe the theory associated with the radius of an atom as it loses on electron.

Loss of electron: When a neutral atom loses one electron to form a cation, its radius decreases. In the cation, the nuclear charge remains the same as that of the parent atom but the number of electrons becomes less. Since the same nuclear charge now attracts the lesser number of electrons, therefore, the force of attraction of the nucleus on the electrons of all the shells increases. i.e. effective nuclear charge per electron increases in the cation and hence the size of the cation decreases. Thus

124 Views

Long Answer Type

113. What do you understand by iso-electronic ions? In iso-electronic ions, the value of ionic radius decreases with the increase in atomic number. Explain.

259 Views

114.

What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions.
(i) F^- (ii) Ar (iii) Mg²⁺ (iv) Rb⁺

216 Views

115.

Consider the following species : N^3-, O^2-, F^-, Na⁺, Mg²⁺ and Al³⁺(a) What is common in them?

(b) Arrange them in the order of increasing ionic radii.

483 Views

Short Answer Type

116. For each of the following pairs, state which one is larger in size and why?
(i) Na, Na⁺ (ii) Br, Br^- (iii) Br, I

132 Views

117.

Give the formula of a species which will be isoelectronic with the following atoms or ions:
(i) Na²⁺
(ii) Cl^-(iii) Ca²⁺
(iv) Rb⁺.

117 Views

118.

Which of the following species will have the largest and the smallest size?
Mg, Mg²⁺, Al, Al³⁺.

690 Views

119.

Arrange the following ions in order of increasing size:
Be²⁺, Cl^-, S^2-, Na⁺, Mg²⁺, Br^-.

935 Views

Long Answer Type

120.

In each of the following pairs, which species has a larger size? Explain.
(i) K or K⁺
(ii) Br or Br^-
(iii) O^2- or F^-(iv) Li⁺ or Na⁺
(v) P or As
(vi) Na⁺ or Mg²⁺

590 Views