tóng​wèi​sù

isotope

同位素 tóng​wèi​sù
isotope
Variants of a chemical element that have the same number of protons and occupy the same position in the periodic table, but have a different number of neutrons; often used in medical diagnosis, biological tracing, and geological dating.

Frequency

Movie subtitles
2.62 per million appears in 1% of films
Written text
2.31 per million

Sources