Question

Question #8fb72

Answer 1

It loses 2 protons with the alpha particle, leaving it with an excess of 2 electrons compared to its new nucleus.

Explanation:

The common `U^(238)` decay to `Th^(234)` is by emission of an alpha particle (`alpha`).

An alpha particle is defined as a positively charged particle of a helium nuclei. An alpha particle is composed of two protons and two neutrons, so it can be represented as a Helium-4 atom. As an alpha particle breaks away from the nucleus of a radioactive atom, it has no electrons, so it has a +2 charge. Therefore, it’s a positively charged particle of a helium nuclei.
http://www.dummies.com/education/science/chemistry/the-process-of-natural-radioactive-decay/

Further in the decay sequence, `U^(234)` decay to `Th^(230)` is also by emission of an alpha particle.

http://legacy.jefferson.kctcs.edu/techcenter/Classes/Physics/AtomicNuclearandModernPhysics/AtomicNuclearandModernPhysics7.html