N₂ refers to nitrogen gas, which consists of a diatomic molecule made up of two nitrogen atoms bonded together by a triple covalent bond.
Diatomic Molecule: A diatomic molecule consists of two atoms chemically bonded together.
Nitrogen Gas (N₂): Nitrogen gas is composed solely of molecules containing two nitrogen atoms joined by a triple covalent bond.
Covalent Bonding: Covalent bonding involves the sharing of electron pairs between atoms.