Classify the following bonds as ionic, polar covalent, or nonpolar covalent. When doing this, please know that

if it is a metal and a nonmetal, it is always ionic. Polar or not is more of a degree than an exact line. Generally,

if the electronegativity is .4 or less, it is nonpolar covalent.

1) Li - Cl

2) B-C

3) N-O

4) Mg - Br

5) C-F

Since F has the highest electronegativity value, can it form a nonpolar covalent bond? Why or why not?