Which pair of atoms has the highest electronegativity difference?

H - S

H - Cl

N - H

O - H

C - H

To find out the electronegativity of each pair, work it out by listing them.

H = 2.2

S = 2.1

N = 3.0 Cl = 3.0

O = 3.5

C = 2.5

H - S - > 2.2 - 2.1 = 0.1

H - Cl - > 2.2 - 3.0 = - 0.8

N - H - > 3.0 - 2.2 = 0.8

O - H - > 3.5 - 2.2 = 1.3

C - H-> 2.5 - 2.2 = 0.3

So, the pairs that has the highest electronegativity is H-Cl and N-H.