Uranium-238 Decay Series (Abbreviated)
•Uranium is found everywhere
on earth
•Uranium decays to Radium
and then to Radon.
•Uranium and Radium as
solids are trapped in soil, but radon gas can
move.
Uranium-238 (solid)
4.47 billion years
Radium-226 (solid)
1,620 years
Radon-222 (gas)
3.8 days