The atomic number of an element E is 16. The number of electrons in its ion E^2– will be :
(a) 16
(b) 18
(c) 15
(d) 14

The atomic number of an element X is 13. What will be the number of electrons in its ion $X^{3+}$?

If the number of protons in one atom of an element Y is 20, then the number of electrons in its ion $Y^{2+}$ will be :

(a) 20

(b) 19

(c) 18

(d) 16