C

Covalent Bond

A:B (shared electron pair) | e.g., H₂: H−H, H₂O: H−O−H
Quick Reference
Formula / NotationA:B (shared electron pair) | e.g., H₂: H−H, H₂O: H−O−H
Also Known AsMolecular bond, Shared electron bond, Electron pair bond

What is Covalent Bond?

A covalent bond is a chemical bond formed by the sharing of one or more pairs of electrons between two atoms, typically between non-metal atoms. Single bonds share one pair, double bonds share two, and triple bonds share three pairs. Covalent bonds result from the overlap of atomic orbitals. Bond strength and length depend on bond order and the atoms involved.

Formula & Notation

A:B (shared electron pair) | e.g., H₂: H−H, H₂O: H−O−H

Other Names / Synonyms: Molecular bond, Shared electron bond, Electron pair bond

Properties & Characteristics

Bond order = number of shared electron pairs (single=1, double=2, triple=3). Bond length decreases with bond order: C−C 154 pm, C=C 134 pm, C≡C 120 pm. Bond energy increases with bond order. Characterized by length (pm or Å), energy (kJ/mol), polarity (dipole moment, Debye). Described by VB theory (orbital overlap) or MO theory (linear combination of AOs). VSEPR predicts geometry from electron pairs.

Uses & Applications

Fundamental to all organic chemistry (C−H, C−C, C=O bonds). Biological macromolecules: peptide bonds in proteins, phosphodiester bonds in DNA, glycosidic bonds in carbohydrates. Polymer chemistry: C−C backbone in polyethylene. Pharmaceutical design based on covalent bond reactivity. Materials science: diamond (C−C network), ceramics.

Safety Information

Covalent bond strength determines reactivity. Weak covalent bonds (O−O peroxides, N−N azo groups) may rupture exothermically — explosion hazard. Strong covalent bonds in polymers make plastics resistant to degradation. Carbon-fluorine bond (very strong, ~488 kJ/mol) makes PFAS compounds environmentally persistent.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Covalent Bond
Formula A:B (shared electron pair) | e.g., H₂: H−H, H₂O: H−O−H
Synonyms Molecular bond, Shared electron bond, Electron pair bond

Frequently Asked Questions

A covalent bond is a chemical bond formed by the sharing of one or more pairs of electrons between two atoms, typically between non-metal atoms. Single bonds share one pair, double bonds share two, and triple bonds share three pairs. Covalent bonds result from the overlap of atomic orbitals. Bond strength and length depend on bond order and the atoms involved.

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