ra.don
radon的音标和读音：
DJ音标发音： [ˈreidɔn]
KK音标发音： [ˈredɑn]
radon的词性：
n.Symbol Rn （名词）符号 Rn
1. 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 86; melting point -71=C; boiling point -61.8=C; specific gravity (solid) 4.See table at element
氡：一种无色、有放射性的惰性气体元素，由镭蜕变产生。在放射疗法中可用作辐射源，在科研中可用于制造中子。它最稳定的同位素是Rn222。半衰期为3.82天。原子序数86；熔点-71=C；沸点-61.8=C；比重（固态）4参见 element
radon的词源：
2. rad(ium)
rad(ium)