The electronegativity value for hydrogen is 2.1, while for chlorine it is 3.16. The electronegativity difference between hydrogen and chlorine in an HCl molecule is:3.16 Cl - 2.1 H = 1.06Since the electronegativity difference is between 0.5 and 1.7, the bond formed between hydrogen and chlorine in an HCl molecule is a polar covalent bond.