Question

Which of the following statements are correct for classification of elements?
I. The properties of elements are periodic functions of their atomic numbers.
II. Non-metallic elements are less in number than the metallic elements.
III. The first ionisation energies of elements along a period do not vary in a regular manner.
IV. The ground state electronic configuration of $Pd(Z=46)$ is $[Kr]4d^{8}5s^2$

• A. I, II, III, IV
• B. I, II, III only
• C. II, III, IV only
• D. I, II, IV only

Answer 1

Answer: (B)

(I, II) Properties of elements are periodic function of their atomic number. Number of non-metals are less as compared to number of metallic elements.

(III) In periodic table, first ionisation energy of elements along a period do not vary in regular manner due to effective nuclear charge.

(IV) Ground state electronic configuration of $Pd[Z=46]$ is $[Kr]4d^{10}5s^0$

Hence, $IVth$ statement is incorrect.