Write the electronic configurations of `Ca and Sr`

Options

A. Due to extra stability of exactly half filled and exactly filled sub shells
B. Because they belong to d-block
C. Both of the above
D. due to the presence of unpaired d-electrons

Answer

A

Explanation

`""_(24)Cr and ""_(29)Cu` have abnormal electronic configuration due to extra stability of half - filled & full filled sub shells.