The statement that is not correct for periodic classification of element isA)The properties of elements are periodic function of their atomic numbers B)Non-metallic elements are less in number than metallic elements C)For transition elements, the 3d-orbitals are filled with electron after 3p-orbitals and before 4s-orbitals D)The first ionisation enthalpies of elements generally increase with increase in atomic number as we go along a period

Options

A. The properties of element are periodic function of their atomic numbers.
B. Non-metallic elements are less in number than metallic elements.
C. For transition elements, the `3d`-orbitals are filled with electrons after `3p`-orbitals and before `4s`-orbitals.
D. The first ionisation enthalpies of element generally increase with increase in atomic number as we go along a period.

Answer

C

Explanation

For transition elements, the `3d`-orbitals are filled with electrons after `4s`-orbitals and before `4p`-orbitals.