| 释义 |
ra·don
\ˈrāˌdän\ noun
(-s)
Etymology: New Latin, from rad- (from radium) + -on
1. : a heavy radioactive gaseous element of the group of inert gases formed by disintegration of radium and used similarly to radium in medicine — symbol Rn; called also radium emanation; see element table, uranium series
2. : an isotope of radon: as
a. : actinon
b. : thoron |