Question

The statement that is not correct for the periodic
classification of elements is
(a) The properties of elements are the periodic
functions of their atomic number.
(b) Non-metallic elements are lesser in number
than metallic elements.
(c) The first ionization energies of elements
along a period do not vary in a regular manner
with increase in atomic number.
(d) For transition elements the d-sub shells are
filled with electrons monotonically with
increase in atomic number.

Answer 1

Answer:

option c is correct answer

Answer 2

d) For transition elements the d-sub shells are  filled with electrons monotonically with  increase in atomic number.

Explanation:

(a) The properties of elements are the periodic functions of their atomic numbers. - Correct.

(b) Non-metallic elements are lesser in number than metallic elements. - Correct.

(c) The first ionisation energies of elements along a period do not vary in a regular manner with increase in atomic number. - Correct.

(d) For transition elements, the d− subshells are filled with electrons monotonically with increase in atomic number. - Incorrect. The d− sub shells are not filled with electrons monotonically with increase in atomic number. There are some exceptions lik Cr, Cu etc.

So option D is incorrect.