A single covalent bond is a type of chemical bond where two atoms share one pair of electrons (i.e., two electrons total). Each atom contributes one electron to the shared pair, allowing both to achieve a stable outer electron configuration.
Key points about a single covalent bond:
- Represented by a single line (–) between two atoms in structural formulas.
- It is the simplest and weakest type of covalent bond compared to double and triple bonds, but it is also the longest.
- Usually formed between nonmetal atoms.
- Allows atoms to satisfy the octet rule (or duet rule for hydrogen).
Examples:
- H₂ (Hydrogen molecule): Each H atom has 1 electron; they share a pair to form H–H.
- Cl₂ (Chlorine molecule): Each Cl atom has 7 valence electrons; they share one pair to complete their octet → Cl–Cl.
- CH₄ (Methane): Carbon shares 4 pairs of electrons with 4 hydrogen atoms, forming four single covalent bonds.