Which pair of atoms forms the most polar bond?
a) N and O
b) C and O
c) C and F
d) N and F
Solution 7SAQ Step 1 of 5 If the difference of electronegativity (EN) between two atoms is 0.4< EN < 1.9 we have a polar covalent bond. Obviously the higher is the difference, the more polar will be the covalent bond. We are going to demonstrate the correct answer is c), by considering the difference of electronegativity values for each pair. Step 2 of 5 Letter (a) For N and O the electronegativity values are 3.0 and 3.5 respectively. Thus EN = 3.5 – 3.0= 0.5 Hence, the electronegativity difference between the two atoms is 0.5. Step 3 of 5 Letter b) For C and O the electronegativity values are 2.5 and 3.5 respectively. Thus EN = 3.5 – 2.5= 1.0 Hence, the electronegativity difference between the two atoms is 1.0.