isotope

Carbon-14 is a radioactive isotope used in archaeological dating of organic materials up to fifty thousand years old.碳-14是一种放射性同位素，用于对年代距今最多五万年的有机材料进行考古测年。

Medical imaging techniques employ radioactive isotopes that emit detectable radiation from within the body.医学成像技术采用放射性同位素，这些同位素会从体内发出可检测到的辐射。