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 $[ Kr ] 4 d^{8}\, 5 s^{2}$

• 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 $[{Kr}] 4 d^{10}\, 5 s^{0}$

Hence, $IV\,th$ statement is incorrect.