I keep reading that when a U-238 atom absorbs a neutron it turns into Pu-239. How does that happen? If I'm not mistaken Pu-239 is U-238 plus 2 protons and 2 electrons and minus 2 neutrons. When U-238 absorbs the neutron and becomes U-239 I can see that it can turn into Pu-239 if 2 neutrons decay into 2 protons + 2 electrons. Is that what happens? Are the electrons expelled like in regular beta decay or do they remain in the nucleus so that a neutral atom is formed rather than an ion?