Which pair of atoms has the highest electronegativity difference?

A. Na-F

B. Ca-F

C. H-F

D. C-F

E. F-F

The B. Ca-F pair has the greatest electronegativity difference.

Electronegativities increase from the lower left to the upper right in the Periodic Table.

Ca is closest to the lower left, and F is in the upper right, so the Ca-F bond has the greatest electronegativity difference.

Answer: Option (B) is the correct answer.

Explanation:

Electronegativity is defined as the ability of an atom to attract an electron towards itself.

Values of electronegativity of the given atoms are as follows.

Sodium = 0.93

Fluorine = 3.98

Calcium = 1.00

Hydrogen = 2.20

Carbon = 2.55

Therefore, electronegativity difference of the given pairs are as follows.

Na-F = 3.98 - 0.93 = 3.05

Ca-F = 3.98 - 1.00 = 1.98

H-F = 3.98 - 2.20 = 1.78

C-F = 3.98 - 2.55 = 1.43

F-F = 3.98 - 3.98 = 0

Hence, we can conclude that the highest electronegativity difference is for pair Ca-F.