# is nitrogen gas a compound

Nitrogen » It is a diatomic nitrogen, a gas molecular entity and an elemental molecule.… Washington, DC: American Chemical Society., 1995., p. 3. Hazardous Substances … Pubchem.ncbi.nlm.nih.gov

Overview of Greenhouse Gases | US EPA » Information on emissions and removals of the main greenhouse gases to and from the atmosphere. Epa.gov

Parts of the Atmosphere » We live at the bottom of an invisible ocean called the atmosphere, a layer of gases surrounding our planet. Nitrogen and oxygen account for 99 percent of the gases in dry air, with argon, carbon dioxide, helium, neon, and other gases making up minute portions. Education.nationalgeographic.org

Nitrogen dioxide » There are seven oxides of nitrogen that may be found in the ambient air. Nitrous oxide (N2O) is a greenhouse gas with significant anthropogenic sources contributing to its worldwide abundance (∼ 0.3 ppm). However, nitric oxide (NO) and nitrogen dioxide (NO2) are the two principal nitrogen oxides associated with combustion sources. Ambient concentrations of these two gases vary widely according to local sources and sinks, but can exceed a total concentration (NO + NO2) of 500 μg/m3 in dense urban areas. Nitrous acid (HONO) is a common pollutant in ambient and indoor environments, produced by the reaction of nitrogen dioxide with water. Ncbi.nlm.nih.gov