What is the decay product of radium-226?

Radium-226 undergoes a radioactive decay process known as alpha decay, during which it emits an alpha particle, resulting in the formation of radon-222 as its decay product. This decay process is part of the uranium-238 decay series, which ultimately leads to lead-206.

Understanding the sequence of decay is crucial. When radium-226 emits an alpha particle, it transforms into an isotope of radon. The significance of this process lies in the stability and properties of the resulting elements; radon-222 is a noble gas and is of particular concern in terms of health and environmental hazards as it can accumulate in homes, especially in geological formations containing uranium.

The other options presented do not represent the immediate decay product of radium-226. Lead-214 and bismuth-214 are further down the decay chain but are not directly formed from radium-226. Radium-228 is a different isotope entirely and does not result from the decay of radium-226. Thus, radon-222 stands out as the direct outcome of radium-226's decay process.