~(222)氡是~(226)镭的直接衰变产物,是惰性气体族中最重的元素,也是铀衰变系中在常温下呈气态的唯一元素。由于氡是气态,因此容易通过岩石和土壤扩散,并且发现在地下矿井、岩洞、甚至一些建筑物地下室内都具有放射学上有意义的浓度。氡的半衰期为3.82天,衰变成钋,铅及铋的同位素。这些所谓的单 ~ (222) Radon is a direct decay product of ~ (226) radium, which is the heaviest element in the noble gas family and the only element in the uranium decay system that is gaseous at normal temperature. Since radon is gaseous, it easily diffuses through rocks and soils and finds radiometrically significant concentrations in underground mines, caves, and even in some building basements. The half-life of radon is 3.82 days, decay into 钋, lead and bismuth isotopes. These so-called single