The chemical formula for nitrous oxide is N₂O.
The formula shows that each molecule contains two nitrogen atoms and one oxygen atom. Nitrous oxide is also called dinitrogen monoxide or, informally, laughing gas. At room temperature it is a colorless, nonflammable gas with a faintly sweet odor and taste.
Nitrous oxide has several very different roles. It is used as an analgesic and anesthetic in medicine and dentistry, as a propellant in whipped-cream dispensers, and as an oxidizer in some rocket and racing applications. Its familiar nickname comes from the euphoria and laughter sometimes associated with inhalation, although misuse can cause serious harm, including vitamin B₁₂-related neurological injury.
The formula is often confused with NO₂, nitrogen dioxide, a different nitrogen oxide containing one nitrogen and two oxygen atoms. Nitrous oxide is also an important greenhouse gas. Agriculture, especially microbial processes in fertilized soils and manure, is a major source of human-caused emissions, and the gas can contribute to stratospheric ozone destruction.