Gaasilisteks

Gaasilisteks is a term used in Estonian to describe substances that exist in the gas phase under typical laboratory or ambient conditions. The concept is employed to distinguish entities in the gaseous state from those in the solid or liquid phases, particularly in discussions of thermodynamics, reaction mechanisms, and environmental processes.

Gas-phase species include a wide range of elements and compounds. Common examples are diatomic molecules such as nitrogen (N2) and oxygen (O2), noble gases like helium (He) and argon (Ar), and various small molecules such as carbon dioxide (CO2), methane (CH4), and water vapor (H2O). The distinguishing feature of gaasilisteks is their low density and high degree of freedom for motion, which affects how they behave in mixtures, reactants, and under pressure.

Properties in the gas phase are often described by the ideal gas approximation at low pressures, where volume is mainly occupied by empty space and inter-molecular forces are weak. Real-gas deviations occur at high pressures or low temperatures. Gas-phase reactions, diffusion, and transport phenomena are central to fields such as combustion, atmospheric chemistry, and analytical techniques. Gas chromatography, for instance, uses a gaseous mobile phase to separate components.

Studying gaasilisteks involves techniques like infrared and Raman spectroscopy, as well as mass spectrometry, to identify and quantify species. The term highlights the importance of phase state in chemical thermodynamics, kinetics, and environmental science.