Question

The electronic configuration of an element is $3d^{5}4s^1$. Its group number is:

• A. 1
• B. 4
• C. 5
• D. 6

Answer 1

The correct option is D 6

From the outer electronic configuration, it is a $d$- block element.

For a $d-$ block element,
$\text{group number = number of (n -1) d electrons + number of ns electrons}$
$=5+1=6$