the world > matter > chemistry > chemical substances > named gases > [noun] > types (3)
a gas which can be liquefied only at very low temperatures (such as oxygen, hydrogen, or air), and was formerly believed to be incapable of…
a gas mixed with a volatile material so that it can be made to flow through an apparatus, e.g. as an inert vector in chromatographic analysis (cf…
any mixture of gases from the flues of chemical or smelting factories.