A binary compound of oxygen with another element or group.
- ‘Nitrates are formed from reacting nitric acid with metal oxides, hydroxides, or carbonates.’
- ‘Exhaust from the automobile can contain carbon monoxide and nitrogen oxides, which are poisonous gases.’
- ‘It would set new caps for nitrogen oxides, sulfur dioxide, and mercury.’
- ‘Power plants will be expected to reduce emissions of mercury, sulfur dioxide, and nitrogen oxides.’
- ‘The gases, particularly sulphur dioxide and oxides of nitrogen, then dissolve in water vapour in the air.’
Late 18th century: from French, from oxygène ‘oxygen’ + -ide (as in acide ‘acid’).
We take a look at several popular, though confusing, punctuation marks.