isotope
nounUK /ˈaɪ.sə.təʊp/
US /ˈaɪ.sə.toʊp/
An isotope is a kind of atom of the same element that has a different number of tiny particles called neutrons.
Carbon-14 is an isotope of carbon that scientists use to find the age of old things.
RELATED WORDS
OTHER MEANINGS
2. Any of two or more forms of the same chemical element that differ in atomic mass but have the same chemical properties.
Hydrogen has three isotopes: protium, deuterium, and tritium.
3. A radioactive form of an element used in medicine or science.
Doctors used a radioactive isotope to scan the patient's bones.
4. A version of something that is slightly different from others of the same kind.
The two proposals are isotopes of the same basic idea.