Knowra Nitrogen dioxide Nitrogen dioxide Nitrogen dioxide (NO₂) is a reddish-brown, toxic gas and reactive nitrogen oxide. It forms during combustion and atmospheric reactions and contributes to smog and acid rain.
Nitrogen oxide : A compound composed of nitrogen and oxygen, including nitric oxide and nitrogen dioxide. Nitrogen dioxide belongs to this family and interconverts with other nitrogen oxides in air.
Combustion : A chemical reaction in which a fuel reacts with an oxidizer, releasing heat and often light. High-temperature combustion produces nitrogen oxides that include nitrogen dioxide.
Chemiluminescence analyzer : An instrument that measures nitrogen oxides by detecting light emitted during a chemical reaction. Air-quality networks use this method to measure NO₂, often after converting it to nitric oxide.
Nitrogen dioxide poisoning : Illness caused by inhaling nitrogen dioxide, which can injure airways and damage lung tissue. Acute exposure can cause severe respiratory injury, sometimes after a delay.
Nitrogen monoxide : A colorless gas with formula NO, also called nitric oxide, that readily reacts with oxygen. Unlike reddish-brown NO₂, NO is colorless and is often emitted directly by combustion.
Nitric oxide : A colorless gas with formula NO that reacts with oxygen to form nitrogen dioxide. This rapid atmospheric reaction is a major route from combustion emissions to NO₂.
Vehicle emissions : Pollutants released by motor vehicles, including nitrogen oxides from engine exhaust. Road traffic is a major urban source of NO₂, especially near busy streets.
Differential optical absorption spectroscopy : A method that identifies atmospheric gases from their absorption of light at characteristic wavelengths. Its open-air measurements can map NO₂ columns above cities and roads.
Asthma : A chronic respiratory disease involving inflamed, narrowed airways and recurring breathing symptoms. NO₂ exposure can irritate airways and worsen asthma symptoms, particularly in susceptible people.
Nitrous oxide : A colorless gas with formula N₂O, used medically and known as a potent greenhouse gas. Its formula and atmospheric role differ sharply from toxic, reactive NO₂.
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