question_answer

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

Correct Answer: A

Solution :

\[F{{e}^{2+}}(z=26)=Ar\,\,3{{d}^{6}}\]   \[C{{r}^{2+}}(z=24)=Ar\,3{{d}^{4}}\]