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general or unspecified; prefer specifics; ISOTOPES and RADIOISOTOPES and many specifics are also available; m for metastable = RADIOISOTOPES or specific precoordinated radioisotope
Scope Note
Substances that comprise all matter. Each element is made up of atoms that are identical in number of electrons and protons and in nuclear charge but may differ in mass or number of neutrons.
Substances that comprise all matter. Each element is made up of atoms that are identical in number of electrons and protons and in nuclear charge but may differ in mass or number of neutrons.