Element details
Look up an element’s symbol, name, atomic number Z and standard atomic weight. Select it to see its naturally occurring isotopes and their abundances.
Atomic number is the number of protons. Isotopes of an element have the same proton count but different neutron counts. To explore them individually, open the Chart of the Nuclides, where every isotope gets its own cell.
Print a copy
Download the one-page PDF to keep beside you while you study. It is designed to remain readable when printed in black and white.
Where the data comes from
Element names, symbols, atomic numbers and standard atomic weights come from the open-source periodictable library, which is public domain. Isotope abundances are the naturally occurring values. The layout and rendering are original.
Presented for training and reference. For operational radiological work, use your site’s controlled references.
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