Radon-222 Decay Chain Radon-222 222 86 days Poloniu n-218 Polonium-210 Polonium-214 218 84 218 84 210 84 Bismuth-214 Bismuth-210 .0002 s iconds days 3 m 138 nutes 214 83 214 83 -210 Leac -206 Lead -214 Lead 5 days 19.7 minutes 206 82 214 82 214 22 years Stable 28.6 minutes Key Alpha particle: ()(, Beta particle: P In the example, Rn is the atomic symbol for the element Radon. The number 222 Rn > indicates the atomic mass of the element (or isotope). The number 86 represents the element's atomic number. ** rnA United States RadTown Radon Activity Set EPA402-B-19-057 Environmental Protection VU Agency https://www.EPA.gov/RadTown/Activity-4-Half-Life-Radon ------- |