Isotopes API
Atomic isotope reference data as an API, built on the NIST Atomic Weights and Isotopic Compositions. For every known nuclide: its element (atomic number Z and symbol), mass number, relative atomic mass, natural isotopic composition (abundance) and the element's standard atomic weight. Look an isotope up by label (C-12, U-238) or by symbol + mass, list every isotope of an element, rank isotopes by mass or natural abundance, or search. A precise physics and chemistry reference for science, education, lab and engineering apps. Distinct from element-level data.
api.oanor.com/isotopes-api
