The goal is to drag element symbols onto their correct positions in the periodic table. A Javascript based periodic table. Some site information is only in Czech language. The Chemical Science and Technology division's Periodic Table describes the history, properties, resources, uses, isotopes, forms, costs, and other information for each element. Features a molecular mass calculator.
Data includes spectroscopic terms and Xcore.
Files only contain elements' symbols, names and atomic number. Map of all known nuclides, with their atomic mass, radioactive decay modes and half-lives, and related information. Brookhaven National Laboratory. Includes thousands of images relating to periodicity and structure. Help build the largest human-edited directory on the web.