The compound NO2 is known as nitrogen dioxide.
Nitrogen dioxide is a reddish-brown gas with a characteristic sharp, biting odor. It is a significant air pollutant and is part of the group of gases referred to as nitrogen oxides (NOx). This compound is formed during combustion processes, such as in vehicles and power plants, where nitrogen in the air combines with oxygen at high temperatures. Understanding nitrogen dioxide is crucial, as it plays a role in forming smog and can have adverse health effects when inhaled.