noun
Scientific term for atoms of the same element with different numbers of neutrons.
炭素14は炭素の同位元素です。
Carbon-14 is an isotope of carbon.
Synonym for 'isotope'; 同位体 is more common in modern scientific contexts, while 同位元素 is slightly more formal or older.
Compound of 同位 (same position) and 元素 (element), referring to atoms occupying the same place in the periodic table.