Radon-222 decays into which element?

Radon-222 is a radioactive noble gas that is a decay product of uranium and thorium. When it undergoes alpha decay, it transforms into Polonium-218. This process is part of the decay chain associated with uranium-238. Polonium-218 is the immediate daughter nuclide of radon-222 in this sequence.

Understanding the decay chain is crucial in radon measurement and mitigation, as knowing the byproducts helps in assessing the potential health risks associated with radon exposure. The transition from radon-222 to polonium-218 is significant in radon health studies because polonium-218 itself is also radioactive and can pose additional risks.

The other elements listed do not represent the direct decay product of radon-222. For instance, uranium-238 is the parent isotope from which radon is derived, while radium-226 and lead-206 are further down the decay chain but not immediately formed from radon-222 decay.