Gassformene

Gassformene, or the gaseous forms, refer to the state of matter in which a substance has neither a fixed shape nor a fixed volume. In gases, particles are far apart, move rapidly, and collide elastically. Because of this, gases fill any container, are highly compressible, and have low density compared with solids and liquids. Temperature and pressure strongly affect gas properties.

Gases can be elemental, such as the diatomic molecules nitrogen (N2), oxygen (O2), and the noble gases helium (He), neon (Ne), and argon (Ar); they can also be compounds like carbon dioxide (CO2), methane (CH4), ammonia (NH3), and water vapor (H2O(g)). Many gases exist as mixtures, such as dry air, which combines several molecular species. It is also common to distinguish between gases at room conditions and vapors, which are the gaseous forms of substances normally found as liquids or solids at room temperature.

The behavior of gases is described by gas laws. The ideal gas law PV = nRT is a useful approximation for many gases under moderate conditions, though real gases deviate at high pressure or low temperature. Boyle’s law, Charles’s law, and Avogadro’s law describe relationships among pressure, volume, temperature, and particle number. Gases can condense to liquids or deposit to solids, and liquids can vaporize to form gases. At very high energy, gases can become plasmas, where a portion of the particles are ionized.

Applications of the gassformene span meteorology, chemistry, industry, and environmental science. Understanding gas forms is essential for designing ventilation and engines, conducting chemical reactions, and studying the Earth’s atmosphere and climate.