The first element of group different form its congeners, i.e. other members of the group in many ways. These differences may be due to the following:
i. Small size of atom and ion.
ii. High electronegativity.
iii. Non-availibility of low lying d-orbitals.
The first element of a group shows resemblence with the second element of the adjacent group on the right. This is known as diagonal relationship.
Lithium exhibits many physical and chemical similarites with magnesium. The reason is:

Options

A. Both have the same size.
B. Both are found in native state.
C. Both have the same ionisation enthalpies.
D. Both have the same electronic configuration.

Answer

A

Explanation

Due to the similarity in size, Li and Mg exhibit diagonal relationship and thus similarities in properties occur.