Question

The number of elements in the transition metal series $Sc$ through $Zn$ that have four unpaired electrons in their $+2$ state are:

• A. $2$
• B. $4$
• C. $5$
• D. $6$

Answer 1

The correct option is A $2$

$F{e}^{2+}(z=26)=\left[Ar\right]3d^6$

$C{r}^{2+}(z=24)=\left[Ar\right]3d^4$