Which molecule contains nonpolar covalent bonds

• A. NaCl
• B. Cl2
• C. He
• D. CO2

Answer: (B)

Nonpolar covalent bonds form when two atoms have nearly identical electronegativities, so they share electrons equally. Chlorine gas is made of two identical chlorine atoms, giving the same electronegativity and an equal sharing of electrons in the bond. Other options involve ionic bonds, or polar covalent bonds where electron sharing is unequal, or in the case of helium, no stable covalent bond forms under normal conditions. So the molecule that contains nonpolar covalent bonds is the diatomic chlorine molecule.