gaseous atmosphere
61hydrogen — /huy dreuh jeuhn/, n. a colorless, odorless, flammable gas that combines chemically with oxygen to form water: the lightest of the known elements. Symbol: H; at. wt.: 1.00797; at. no.: 1; density: 0.0899 g/l at 0°C and 760 mm pressure. [1785 95;… …
62photosynthesis — photosynthetic /foh teuh sin thet ik/, adj. photosynthetically, adv. /foh teuh sin theuh sis/, n. Biol., Biochem. (esp. in plants) the synthesis of complex organic materials, esp. carbohydrates, from carbon dioxide, water, and inorganic salts,… …
63isotope — 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… …
64Xenon — (PronEng|ˈzɛnɒn [Xenon, entry in the Oxford English Dictionary, prepared by J. A. Simpson and E. S. C. Weiner, vol. 20, second edition, Oxford: Clarendon Press, 1989. ISBN 0 19 861232 X (vol. 20), ISBN 0 19 861186 2 (set.)] or IPAlink en|ˈziːnɒn… …
65Compilation of atmospheric dispersion models — Atmospheric dispersion models are computer programs that use mathematical algorithms to simulate how pollutants in the ambient atmosphere disperse and, in some cases, how they react in the atmosphere. The dispersion models are used to estimate or …
66coal — 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… …
67solar system — the sun together with all the planets and other bodies that revolve around it. [1695 1705] * * * The Sun, its planets, and the small bodies (see asteroid, Centaur object, comet, Kuiper belt, meteorite, and Oort cloud) interplanetary dust and gas… …
68Gas giant — A gas giant (sometimes also known as a Jovian planet after the planet Jupiter, or giant planet) is a large planet that is not primarily composed of rock or other solid matter. There are four gas giants in our Solar System: Jupiter, Saturn, Uranus …
69Rocket engine — RS 68 being tested at NASA s Stennis Space Center. The nearly transparent exhaust is due to this engine s exhaust being mostly superheated steam (water vapor from its propellants, hydrogen and oxygen) …
70cluster — clusteringly, adv. clustery, adj. /klus teuhr/, n. 1. a number of things of the same kind, growing or held together; a bunch: a cluster of grapes. 2. a group of things or persons close together: There was a cluster of tourists at the gate. 3. U.S …
