isotope
noun /ˈaɪsətəʊp/
/ˈaɪsətəʊp/
(physics, chemistry)- 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.
- radioactive isotopes
- the many isotopes of carbon
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).