同位素 tóngwèisù isotope Origin Definitions Defs Strokes Stroke Words Sentences Sents 可裂变同位素 kělièbiàntóngwèisù fissionable isotope 同位素分离 tóngwèisùfēnlí isotope separation isotopic separation放射性同位素 fàngshèxìngtóngwèisù radioisotope An isotope that is unstable and undergoes radioactive decay, emitting radiation.