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CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

Single bond

A covalent bond made of one shared pair of electrons (bond order 1), drawn as one line. It is the longest and weakest bond between a given pair of atoms.

σ bond: head-on overlapTwo p orbitals on neighbouring atoms point straight at each other along the bond axis; they overlap in the region between the two nuclei, which is where the σ bond's electron density sits.bond axisABoverlap on the axiselectron density between the nuclei → σ bond(s + s, s + p and end-on p + p all give σ)

A single bond is one σ\sigma bond: overlap along the bond axis.

Example

C–C in ethane is 154 pm long, versus 134 pm for C=C and 120 pm for C≡C.

See alsoMultiple bondCovalent bondσ bond (sigma bond)Bond length