Which of the following is not correct statement for periodic classification of elements?

Options

A. The properties of the elements are the periodic functions of their atomic numbers
B. Non - metallic elements are lesser in number than the metallic elements
C. The first ionization energies of the elements along a period do not vary in a regular manner with increase in atomic number
D. For transition elements , the d - electrons are filled monotonically with increase in atomic number

Answer

D