question_answer

Number of electron having the quantum numbers \[n=4,\,\ell =0,\,s=-\frac{1}{2}\]  in \[Z{{n}^{+2}}\] ion is/are:

A) 1

B) 0                

C) 2 

D) 5

Correct Answer: B

Solution :

[b] Electronic configuration of\[Z{{n}^{2+}}\]ion is \[1{{s}^{2}}2{{s}^{2}}\]\[2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}3{{d}^{10}}\]so no electron inorbitals.