Which of the following would you expect to form an ionic bond when combined?

Ba2+ and Mg 2+

Ca2+ and F-

Cl- and O2-

N and O

Question

Which of the following would you expect to form an ionic bond when combined? 
		
Ba2+ and Mg 2+
		
Ca2+ and F-
		
Cl- and O2-
		
N and O

chillout · Answer

We expect an ionic bonding whenever we see two horizontally "very distant" elements forming a bond (Rigorously, we define an ionic bonding when we have a difference of over 1.7 in their electronegativity.). Thus, following this simple rule, Calcium and Fluorine are expected to have an ionic bonding.