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ra·don AHD[rāʹdŏn] D.J.[ˈreɪdɒn]K.K.[ˈredɑn]n.Symbol Rn （名词）符号 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 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
- rad(ium) rad(ium)
- -on 2-on2
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