Covalent Bond – All About

For this you need the electronegativity values ​​of these elements.

EN(Na) = 0.93

EN(Cl) = 3.16

EN(H) = 2.2

The electronegativity difference for Na and Cl is: 3.16 – 0.93 = 2.23 > 1.7

So an ionic bond.

The electronegativity difference for H and Cl is:

3.16 – 2.2 = 0.96 < 1.7

So a polar covalent bond because 0.96 is also larger than 0.5.