one of two or more forms of a chemical element that have the same number of protons but a different number of neutrons in their atoms. They have different physical properties (= characteristics) but the same chemical ones. 同位素 radioactive isotopes 放射性同位素 the many isotopes of carbon 碳的诸多同位素
Oxford Collocations DictionaryIsotope is used after these nouns:- carbon
Word Origin1913: coined by F. Soddy, from iso- ‘equal’ + Greek topos ‘place’ (because the isotopes occupy the same place in the periodic table of elements).