In the realm of nuclear physics, a process in which a nucleus loses protons is known as nuclear decay or radioactive decay. Specifically, there are a few different types of radioactive decay processes through which a nucleus can lose protons:
Alpha decay: In alpha decay, a nucleus emits an alpha particle, which consists of two protons and two neutrons (essentially a helium nucleus). As a result, the original nucleus loses two protons, resulting in a new element with an atomic number two less than the original.
Proton emission: Certain highly unstable nuclei can undergo proton emission, where a proton is spontaneously ejected from the nucleus. This results in the original nucleus losing a single proton and transforming into a different element.
Spontaneous fission: In rare cases, heavy and highly unstable nuclei can undergo spontaneous fission, where the nucleus splits into two smaller nuclei. During this process, protons can be lost from the original nucleus, leading to the formation of two or more smaller nuclei.
It's important to note that the loss of protons from a nucleus through these decay processes changes the atomic number of the nucleus, which defines the element. Therefore, the decay products are typically different elements than the original nucleus.