

In contrast, French-American historian Jacques Barzun speculated that Van Helmont had borrowed the word from the German Gäscht, meaning the froth resulting from fermentation. That story is given no credence by the editors of the Oxford English Dictionary. Īn alternative story is that Van Helmont's term was derived from " gahst (or geist), which signifies a ghost or spirit". According to Paracelsus's terminology, chaos meant something like "ultra-rarefied water". Van Helmont's word appears to have been simply a phonetic transcription of the Ancient Greek word χάος Chaos – the g in Dutch being pronounced like ch in "loch" (voiceless velar fricative, / x/) – in which case Van Helmont was simply following the established alchemical usage first attested in the works of Paracelsus.

He identified carbon dioxide, the first known gas other than air. The word gas was first used by the early 17th-century Flemish chemist Jan Baptist van Helmont. When grouped together with the monatomic noble gases – helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn) – these gases are referred to as "elemental gases". The only chemical elements that are stable diatomic homonuclear molecules at STP are hydrogen (H 2), nitrogen (N 2), oxygen (O 2), and two halogens: fluorine (F 2) and chlorine (Cl 2). 5.4 Intermolecular forces - the primary difference between Real and Ideal gases.5.2 Thermal motion and statistical mechanics.For a comprehensive listing of these exotic states of matter see list of states of matter. High-density atomic gases super-cooled to very low temperatures are classified by their statistical behavior as either Bose gases or Fermi gases. Bounding the lower end of the temperature scale lie degenerative quantum gases which are gaining increasing attention. The gaseous state of matter occurs between the liquid and plasma states, the latter of which provides the upper temperature boundary for gases. This separation usually makes a colourless gas invisible to the human observer. What distinguishes a gas from liquids and solids is the vast separation of the individual gas particles. A gas mixture, such as air, contains a variety of pure gases. oxygen), or compound molecules made from a variety of atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. Ī pure gas may be made up of individual atoms (e.g. Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma).
