Physics, chemistry: alpha particles from radioactive decay

Self-tutoring about radioactive decay: the tutor wonders what happens to emitted alpha particles.

An alpha particle – sometimes written α – can be emitted in various radioactive decay scenarios. U²³⁸ → Th²³⁴ + α is an example.

α particles aren’t seen as dangerous radiation compared to some kinds, because they don’t penetrate the body the way some types of radiation do. The only way I know of that α radiation can be dangerous is if a person ingests material that releases it; such a situation is hard to imagine.

Yet, what happens to the α particles after release? An α particle is a helium nucleus without electrons. After emission, it eventually gains two electrons to become a helium atom. It may, however, ionize up to 100,000 other species it encounters on the way.

Source:

chem.uiuc.edu