"Radioactive Element"^^ . "C0013880"^^ . "Pharmacologic Substance"^^ . . . . "C465"^^ . . "Radioactive_Element"^^ . "Radioactive Element"^^ . "Element, Ion, or Isotope"^^ . "Elements which exhibit atomic emission due to natural or artificial nuclear transformation. These elements spontaneously undergo radioactive decay.MSH2002_06_01" . "Radioactive ElementPTNCI" . "Elements, radioactiveSYNCI" .