Answer:
Bromine (option A) at 2.96 comes the closest to that value 3.03.
Step-by-step explanation:
Step 1: Data given
The electronegativity difference between the elements of NaX (Na and X) is 2.1.
Step 2: Calculate the electronegativity difference
electronegativity difference of Na = 0.93
Na = 0.93
2.1 + 0.93 = 3.03
Electronegativity of the 4 elements
Br = 2.96
Cl = 3.16
F = 3.98
O = 3.44
Bromine (option A) at 2.96 comes the closest to that value 3.03.