Question

The group number, number of valence electrons, and highest possible value of oxidation number of element having atomic number $25$, respectively, are:

• A. $7,2\text{and}+7$
• B. $7,7\text{and}+7$
• C. $5,7\text{and}+2$
• D. $5,7\text{and}+7$

Answer 1

The correct option is B $7,7\text{and}+7$

The element with atomic number $\left(Z\right)=25$ is Manganese.
Electronic configuration of Manganese:
$Mn\to \left[Ar\right]4s^{2}3d^5$
Number of valence electrons $=7$
So, Manganese belongs to group number $7$.
The highest possible value of oxidation number of $Mn$ is $+7$