the bond between which pair of elements is the least ionic in character ?

(1) H-F
(2)H-Cl
(3) H-I
(4) H-O
please help

1 answer

Look up the electronegativity (EN). The ionic character of the bond can be estimated by subtracting the EN of each element. For example, H is 2.1 and F is 4.0, the difference is 1.9. Do the same for the others. The larger the the difference, the more ionic in character is the bond.