WebElements Periodic Table of the Elements | Periodicity | Isotope abundances | periodicity

	Isotope abundances The isotopic abundances are representative isotopic compositions of chemicals most likely to be encountered in the laboratory. Units None Notes The abundances need not necessarily correspond to the most common source of the material. So, the values quoted for hydrogen is for fresh water in a temperate climate rather than ocean water. Values in parentheses represent ranges for probable variations in the materials as well as experimental errors. Literature sources K.J.R. Rosman and P.D.P. Taylor for International Union of Pure and Applied Chemistry in Isotopic Compositions of the Elements 1997, Pure and Applied Chemistry, 1998, 70, 217. [Copyright 1997 IUPAC] WebElements Shop WebElements now has an online shop at which you can buy periodic table posters, mugs, T-shirts, games, molecular models, and more.
Periodicity		Search WebElements Search Chemistry Web Custom Search Essential data Essential data: name, symbol, atomic number, and atomic weight; block, period, group number, and group name in periodic table; description; standard state; registry number; and isolation History: meaning of name; discovery; and history of the element Find a property The elements round us Uses Geology: Abundance of elements in the universe; the sun; meteorites; Earth's crust; oceans; and streams Biology: abundance in humans; biological role; and health hazards Compounds Compounds: halides, oxides, sulfides, hydrides, and complexes; lattice energies; and reduction potentials Electronegativities: Pauling; Sanderson; Allred-Rochow; Mulliken-Jaffe; and Allen Bond enthalpies of diatomic species Lattice energies: oxides and halides Element properties Physics properties: boiling point; melting point; density; and molar volume; thermal conductivity; and electrical resistivity; bulk modulus; critical temperature; superconductivity temperature; hardness (mineralogical, Brinell, and Vickers); linear expansion coefficient; Poisson's ratio; reflectivity; refractive index; rigidity modulus; Young's modulus; and velocity of sound Images Allotropes Reactions of : reactions with air; water; halogens; acids; and bases Crystal structure Thermochemistry: enthalpies of atomisation, fusion, and vaporisation, thermodynamic properties Atom properties Electronic properties: electronic configuration; term symbol; electron affinity; ionisation energies; and atomic spectra Atom sizes: atomic radii; Shannon and Pauling Ionic radii; covalent radius; metallic radius; element bond length; and Van der Waals radius Electron shell properties: effective nuclear charge; electron binding energies; and valence orbital radii maxima Nuclear properties Isotopes: isotope abundances; radioactive isotopes; isotope masses; nuclear spins; and nuclear magnetic moments NMR properties: frequencies; NMR isotopes; magnetogyric ratios; quadrupole moments; receptivities; and relative sensitivities Books Chemistry Books (CA) Chemiebücher (DE) Livres de chimie (FR) Medical Bookshop (UK) Medical Bookstore (USA) Physics Bookshop (UK) Biology Bookshop (UK) Law, Business, and Finance Bookshop (UK) Scientific book store (USA) Scientific book store (UK)