Positron decay transforms a proton into what particle?

In the process of positron decay, also known as beta plus decay, a proton within the nucleus of an atom is transformed into a neutron. This transformation occurs when a proton emits a positron, which is the antimatter equivalent of an electron, along with a neutrino.

The key aspect of positron decay is that the overall charge of the atom remains unchanged; hence, a proton is converted into a neutron, effectively reducing the atomic number by one while keeping the mass number constant. This process is significant in the context of nuclear reactions, as it helps explain certain types of radioactive decay and the resulting emissions.

The emitted positron and neutrino play important roles in the overall decay process, but it is the conversion of the proton into a neutron that is central to the question. An understanding of this decay process is fundamental to the principles of nuclear physics and medical applications such as positron emission tomography (PET).