noun
stable isotope
Technical term in physics and chemistry. Refers to isotopes that do not undergo radioactive decay.
炭素の安定同位体には炭素12と炭素13がある。
Stable isotopes of carbon include carbon-12 and carbon-13.
Radioactive isotope; contrasts with 安定同位体, which does not decay.
Compound of 安定 (stable) + 同位体 (isotope).