gaser

Gaser is the plural form of gas in several Scandinavian languages, notably Swedish where gaser refers to gases in general. In Norwegian and Danish the spelling varies (gasser in those languages), reflecting differences in orthography. Outside of Scandinavian usage, the form may appear in language contexts as a generic reference to gaseous substances.

In science, a gas is one of the four fundamental states of matter, characterized by a lack of fixed shape and volume, the ability to expand to fill a container, and the tendency to diffuse and mix with other gases. Gas particles move rapidly and interact weakly under ordinary conditions, though interactions become relevant at high pressures or low temperatures.

Gases are described by models such as the ideal gas law, PV = nRT, which relates pressure, volume, temperature, and amount of substance under many conditions. Real gases deviate from the ideal model at high pressures or low temperatures, and corrections (for example via the van der Waals equation) account for molecular size and interactions.

Common examples include nitrogen (N2) and oxygen (O2) in Earth's atmosphere, as well as argon (Ar), carbon dioxide (CO2), methane (CH4), and other noble and reactive gases. Air is a mixture containing nitrogen, oxygen, argon, carbon dioxide, water vapor, and trace gases, each contributing to its properties.

Gases play central roles in chemistry, physics, and environmental science. They are essential for respiration, combustion, and industrial processes, while greenhouse gases such as CO2, methane, and nitrous oxide have significant implications for climate and air quality. Understanding gas behavior aids research across disciplines and in practical applications.