* Oxygen gas (O₂) is a diatomic molecule, meaning it consists of two oxygen atoms.

* The bond between the two oxygen atoms in O₂ is a nonpolar covalent bond. This is because:

* Oxygen atoms have the same electronegativity. Electronegativity is the ability of an atom to attract electrons in a bond. Since they have the same electronegativity, the electrons in the bond are shared equally.

* The molecule is symmetrical. The two oxygen atoms are identical and the bond is symmetrical, meaning there's no separation of charge.

In contrast, a polar covalent bond occurs when two atoms with different electronegativities share electrons. This results in a partial positive charge on one atom and a partial negative charge on the other.

Examples of polar covalent bonds:

* Water (H₂O): Oxygen is more electronegative than hydrogen, resulting in a polar molecule.

* Carbon monoxide (CO): Oxygen is more electronegative than carbon, creating a polar bond.