isotopic mass
71Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
72Kinetic isotope effect — The kinetic isotope effect (KIE) is the ratio of reaction rates of two different isotopically labeled molecules in a chemical reaction. It is also called isotope fractionation, although this term is somewhat broader in meaning. A KIE involving… …
73Isotope — This article is about the atomic variants of chemical elements. For the British jazz fusion band, see Isotope (band). Isotopes redirects here. For the minor league baseball team, see Albuquerque Isotopes. Isotopes are variants of atoms of a… …
74Atomic weight — (symbol: A sub|r) is a dimensionless physical quantity, the ratio of the average mass of atoms of an element (from a given source) to 1/12 of the mass of an atom of carbon 12.cite journal | author = International Union of Pure and Applied… …
75Kilogram — Kg redirects here. For other uses, see Kg (disambiguation). Kilogram A computer generated image of the international prototype kilogram (IPK). The IPK is the kilogram. The IPK, which is roughly the size of a golf ball, sits here alongside a ruler …
76Impact event — Artist s impression of a major impact event. The collision between Earth and an asteroid a few kilometers in diameter may release as much energy as several million nuclear weapons detonating simultaneously. An impact event is the collision of a… …
77Radiometric dating — (often called radioactive dating) is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.[1]… …
78Pleistocene Epoch — Earlier and longer of the two epochs that constitute the Quaternary Period. The Pleistocene began с 1.8 million years ago and ended с 10,000 years ago. It was preceded by the Pliocene Epoch of the Tertiary Period and followed by the Holocene… …
79Isotopes of lithium — Naturally occurring lithium (Li) (standard atomic mass: 6.941(2) u) is composed of two stable isotopes (SimpleNuclide|Lithium|6 and SimpleNuclide|Lithium|7, the latter being the more abundant (92.5% natural abundance). Seven radioisotopes have… …
80hydrosphere — /huy dreuh sfear /, n. the water on or surrounding the surface of the globe, including the water of the oceans and the water in the atmosphere. [1885 90; HYDRO 1 + SPHERE] * * * Discontinuous layer of water at or near the Earth s surface. It… …
