A chemical bond in which one pair of electrons is shared between two atoms.
- ‘In the nitro group, the central nitrogen atom is involved in both a double bond and a single bond.’
- ‘Like other hydrocarbons with double bonds, addition reactions can occur to change the double bonds to single bonds.’
- ‘The porphyrin ring is unsaturated, having alternating carbon-carbon single bonds and double bonds throughout the ring.’
- ‘A carbon atom with two single bonds and one double bond carries a valence of four.’
- ‘If a single bond is made by sharing one electron from each atom, each oxygen then has seven electrons, one short of an octet.’
We take a look at several popular, though confusing, punctuation marks.