single bond

single bond, type of chemical bond in which two atoms share one pair of electrons, one electron from each atom. It is represented by a single line (―) between the two atoms in structural formulas. Single bonds are the simplest and weakest type of covalent bond, but because they have a lower electron density, they are also the most stable in many organic and inorganic molecules.

An example of a single bond is in a hydrogen molecule (H₂), where each hydrogen atom shares one electron with the other. Similarly, in methane (CH₄), each of the four hydrogen atoms forms a single bond with the central carbon atom.