the isotopic composition of all elements
121New Frontiers program — For other uses, see New Frontier (disambiguation). The spacecraft New Horizons launched in 2006 towards Pluto The New Frontiers program is a series of space exploration missions being conducted by NASA with the purpose of researching several of… …
122metabolism — /meuh tab euh liz euhm/, n. 1. Biol., Physiol. the sum of the physical and chemical processes in an organism by which its material substance is produced, maintained, and destroyed, and by which energy is made available. Cf. anabolism, catabolism …
123Mapping class group — In mathematics, in the sub field of geometric topology, the mapping class group is an important algebraic invariant of a topological space. Briefly, the mapping class group is a discrete group of symmetries of the space. Contents 1 Motivation 2… …
124Magnesium — Not to be confused with Manganese. sodium ← magnesium → aluminium Be ↑ Mg ↓ Ca …
125Homotopy — This article is about topology. For chemistry, see Homotopic groups. The two dashed paths shown above are homotopic relative to their endpoints. The animation represents one possible homotopy. In topology, two continuous functions from one… …
126Isotopes of neptunium — Neptunium (Np) is an artificial element, and thus a standard atomic mass cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 239Np in 1940, produced by bombarding 238U with neutrons to …
127Earth, geologic history of — Introduction evolution of the continents, oceans, atmosphere, and biosphere. The layers of rock at the Earth s surface contain evidence of the evolutionary processes undergone by these components of the terrestrial environment during the… …
128Xenon — (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… …
