Radon-222

Main isotopes of radon

iso NA half-life DM DE (MeV) DP 210Rn syn 2.4 h α 6.404 206Po 211Rn syn 14.6 h ε 2.892 211At α 5.965 207Po 222Rn trace 3.8235 d α 5.590 218Po 224Rn syn 1.8 h β− 0.8 224Fr

There are 39 known isotopes of radon (₈₆Rn) from ¹⁹³Rn to ²³¹Rn; all are radioactive. The most stable isotope is ²²²Rn with a half-life of 3.823 days. Four isotopes, ^{218, 219, 220, 222}Rn occur in trace quantities in nature as decay products of, respectively, ²¹⁸At, ²²³Ra, ²²⁴Ra, and ²²⁶Ra. ²¹⁸Rn and ²²²Rn are intermediate steps in the decay chain for ²³⁸U, ²¹⁹Rn is an intermediate step in the decay chain for ²³⁵U and ²²⁰Rn occurs in the decay chain for ²³²Th.

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