All the data has been painstakingly compiled from international standards and recommendations by the International Union of Pure and Applied Chemistry, is 100 % error–free and conforms to the latest published information.
A miniature database of chemical and physical information; handy for studying, teaching, and research.
relative atomic mass
number and abundance of natural isotopes
longest–lived radioisotope, type of decay
abundance in the earth′s crust
first ionization energy
melting and boling point
ionic radius by oxidation number
van der Waals radius
Klaus Heumann is the former Professor of Analytical Chemistry at the University of Mainz (Germany). He is a long–time member of the IUPAC commission on isotope abundances and atomic weights, in which capacity he is actively involved in shaping the IUPAC recommendations on chemical element data.