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

Options

A. 1. The properties of elements are periodic functions of their atomic numbers
B. 2. Non-metallic elements are leser in number than metallic elements
C. 3. The first ionisation energies of elements along a period do not vary in regular manner with increase in atomic number.
D. 4. For transition elements, the d- subshells are filled with elements monotonically with increase in atomic number.

Answer

C

Explanation

No regular order. For example
`Li lt Be, Be gt B, B lt C, C lt N, N gtO, O lt F`