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 .

Step-by-step solution

(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 d¹⁰ 5 s^0 . Hence, IVth statement is incorrect. Thus, option (b) is correct.