In beta decay, a neutron becomes a _____.

In beta decay, a neutron transforms into a proton through a process that involves the emission of a beta particle, which is either an electron or a positron, depending on the type of beta decay occurring. In the case of beta minus decay, it is a neutron that decays into a proton while emitting an electron and an antineutrino. As a proton remains in the nucleus, the atomic number of the element increases by one, but the mass number remains unchanged.

Understanding this concept is essential in the study of nuclear reactions and radioactive decay processes. The conversion of a neutron to a proton is a fundamental aspect of beta decay, leading to various applications in fields such as nuclear medicine and radiobiology. It's important to note that while the decay emits an electron, the transformation specifically highlights the neutron changing into a proton, which is why this answer is correct.