名詞 radon:

1. a radioactive gaseous element formed by the disintegration of radium; the heaviest of the inert gasses; occurs naturally (especially in areas over granite) and is considered a hazard to health
   同義詞：Rn, atomic number 86

1. Any of several radioactive gases that are isotopes of radon and are products of radioactive decay.
   射氣幾種氡的同位素的放射性氣體，是放射性物質(zhì)衰變的產(chǎn)物
2. A radioactive, inert, gaseous isotope of radon, with a half-life of3.92 seconds.
   錒射氣氡的一種放射性的，惰性的和氣態(tài)的同位素，其半衰期為3。92秒

ra.don

n.Symbol Rn （名詞）符號 Rn
A colorless, radioactive, inert gaseous element formed by the radioactive decay of radium. It is used as a radiation source in radiotherapy and to produce neutrons for research. Its most stable isotope is Rn 222 with a half-life of 3.82 days. Atomic number 8'; melting point -7=C; boiling point -'.8=C; specific gravity (solid) 4.See table at element
氡：一種無色、有放射性的惰性氣體元素，由鐳蛻變產(chǎn)生。在放射療法中可用作輻射源，在科研中可用于制造中子。它最穩(wěn)定的同位素是Rn222。半衰期為3.82天。原子序數(shù)8'；熔點-7=C；沸點-'.8=C；比重（固態(tài)）4參見 element

來源：
rad(ium)
rad(ium)
-on 2
-on2