Which pair of elements would form a nonpolar covalent bond?

A. bismuth and sulfur

B. carbon and oxygen

C. nitrogen and oxygen

D. silicon and phosphoro

Answer is: D. silicon and phosphorus.

When the electronegativity difference is greater, the bond polarity is increasing ...

Electronegativity (χ) is a property that describes the tendency of an atom to attract a shared pair of electrons.

Atoms with higher electronegativity attracts more electrons towards it, electrons are closer to that atom.

A) Δχ (Bi-S) = 2.5 - 2.0 = 0.5; polar covalent.

B) Δχ (C-O) = 3.5 - 2.5 = 1.0; polar covalent.

C) Δχ (N-O) = 3.5 - 3 = 0.5; polar covalent.

D) Δχ (Si-P) = 2.2 - 1.9 = 0.3; nonpolar covalent.