radon

n. 氡

A radioactive, inert, gaseous isotope of radon, with a half-life of3.92 seconds.

锕射气氡的一种放射性的，惰性的和气态的同位素，其半衰期为3。92秒

Any of several radioactive gases that are isotopes of radon and are products of radioactive decay.

射气几种氡的同位素的放射性气体，是放射性物质衰变的产物