gaseous hydrogen
121liquid — liquidly, adv. liquidness, n. /lik wid/, adj. 1. composed of molecules that move freely among themselves but do not tend to separate like those of gases; neither gaseous nor solid. 2. of, pertaining to, or consisting of liquids: a liquid diet. 3 …
122petroleum refining — Introduction conversion of crude oil into useful products. History Distillation of kerosene and naphtha The refining of crude petroleum owes its origin to the successful drilling of the first oil well in Titusville, Pa., in 1859. Prior to… …
123isotope — isotopic /uy seuh top ik/, adj. isotopically, adv. /uy seuh tohp /, n. Chem. any of two or more forms of a chemical element, having the same number of protons in the nucleus, or the same atomic number, but having different numbers of neutrons in… …
124Helium — otherusesHelium (He) is a colorless, odorless, tasteless, non toxic, inert monatomic chemical element that heads the noble gas group in the periodic table and whose atomic number is 2. Its boiling and melting points are the lowest among the… …
125Oxygen — This article is about the chemical element and its most stable form, O2 or dioxygen. For other forms of this element, see Allotropes of oxygen. For other uses, see Oxygen (disambiguation). nitrogen ← oxygen → fluorine ↑ O ↓ …
126comet — cometary /kom i ter ee/, cometic /keuh met ik/, cometical, adj. cometlike, adj. /kom it/, n. Astron. a celestial body moving about the sun, usually in a highly eccentric orbit, consisting of a central mass surrounded by an envelope of dust and… …
127oxyacid — /ok see as id/, n. Chem. an inorganic acid containing oxygen. Also called oxygen acid. [1830 40; OXY 2 + ACID] * * * ▪ chemical compound Introduction any oxygen containing acid. Most covalent nonmetallic oxides (oxide) react with water to… …
128coal — coalless, adj. /kohl/, n. 1. a black or dark brown combustible mineral substance consisting of carbonized vegetable matter, used as a fuel. Cf. anthracite, bituminous coal, lignite. 2. a piece of glowing, charred, or burned wood or other… …
