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
Topics Physics and chemistryc2Oxford Collocations DictionaryIsotope is used after these nouns: See full entry 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).