isotope fractionation
41rare-earth element — /rair errth /, Chem. any of a group of closely related metallic elements, comprising the lanthanides, scandium, and yttrium, that are chemically similar by virtue of having the same number of valence electrons. Also called rare earth metal. [1955 …
42Isotopic signature — An isotopic signature (also isotopic fingerprint) is a ratio of stable or unstable isotopes of particular elements found in an investigated material. The atomic mass of different isotopes affect their chemical kinetic behavior, leading to natural …
43Isotopes of hydrogen — Hydrogen (H) (Standard atomic mass: 1.00794(7) u) has three naturally occurring isotopes, denoted 1H, 2H, and 3H. Other, highly unstable nuclei (4H to 7H) have been synthesized in the laboratory but not observed in nature.Gurov YB, Aleshkin DV,… …
44Isotopes of uranium — Uranium (U) is a naturally occurring element with no stable isotopes. In other words, all uranium is radioactive and hence vanishing by radioactive decay, yet it is also found in great quantity in the earth s crust. The natural isotopes are… …
45Si-Isotopenfraktionierung — Die Si Isotopenfraktionierung ist die massenabhängige Isotopenfraktionierung im Promille Bereich der relativen Verhältnisse der stabilen Isotope des Siliciums. Bei den stabilen Isotopen des Siliciums handelt es sich um die sogenannten „nicht… …
46chemical element — Introduction also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed. This article considers the… …
47Isotopes 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… …
48geology — /jee ol euh jee/, n., pl. geologies. 1. the science that deals with the dynamics and physical history of the earth, the rocks of which it is composed, and the physical, chemical, and biological changes that the earth has undergone or is… …
49Proxy (climate) — Climate proxies are preserved physical characteristics of the past that enable scientists to reconstruct the climatic conditions that prevailed during much of the Earth s history. As reliable modern records of climate only began in the 1880s,… …
50Isotopes of chlorine — Chlorine (Cl) has 24 isotopes with mass numbers ranging from 28Cl to 51Cl and 2 isomers (34mCl and 38mCl). There are two principal stable isotopes, 35Cl (75.78%) and 37Cl (24.22%), found in the relative proportions of 47.89:12.11, not 3:1,… …
