radon | (n) 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, Syn. Rn, atomic number 86 |
氡 | [氡] radon Rn, noble gas, atomic number 86 #31,040 [Add to Longdo] |