Definition of a Diatomic Molecule
A diatomic molecule is a molecule composed of only two atoms, regardless of whether those atoms are of the same or different chemical elements. The prefix "di-" explicitly indicates the presence of two atoms in the molecular structure.
Formation and Key Characteristics
These molecules typically form when two atoms achieve a stable electron configuration by sharing electrons, usually through a covalent bond. For elemental diatomic molecules, this bonding often allows each atom to satisfy the octet rule (or duet rule for hydrogen), making the molecule significantly more stable than individual isolated atoms.
Common Examples in Chemistry
The most well-known examples are the seven diatomic elements: hydrogen (H₂), nitrogen (N₂), oxygen (O₂), fluorine (F₂), chlorine (Cl₂), bromine (Br₂), and iodine (I₂). Other common diatomic molecules with different elements include carbon monoxide (CO) and hydrogen chloride (HCl).
Importance in Nature and Industry
Diatomic molecules are fundamental to life and industrial processes. Oxygen (O₂) is crucial for respiration in living organisms, while nitrogen (N₂) constitutes about 78% of Earth's atmosphere and is essential for synthesizing proteins and nucleic acids. Understanding them is key to grasping chemical reactions and the composition of matter.