The statement that is not correct for the periodic classification of elements is

Options

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 ionisation energies 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

C

Explanation

Along a period in general from left to right `I.E^(1)` value increases.