Question

What is the number of unpaired electrons in a manganese atom ($Z=25$) in its lowest energy states?

• A. $1$
• B. $3$
• C. $5$
• D. $7$

Answer 1

Answer: (C)

$5$

In its lowest energy state, the configuration of $Mn$ is $\left[Ar\right]4s^{2}3d^5$.
Hence it has 5 unpaired electrons. Therefore option C is the right answer.