If plutonium (element 94) decays into uranium (element 92), what type of radiation is released?

Alpha particles

Explanation:

When plutonium radioactively decays to uranium, an alpha particle results.

Alpha particles are similar in nature to a Helium cation in that they have a nucleus made up of 2 protons and 2 neutrons. They are the only type of radiation with an atomic number of 2.

If Pt-94 breaks down to U-92, a loss of 2 protons result and it will be balanced by the alpha particle produced.