Final answer:
The student's question involves the subject of Physics, specifically the behavior of unstable subatomic particles observed through scientific investigation. These particles can change into other particles, a phenomenon exemplified in processes like radioactive decay.
Step-by-step explanation:
The student's question relates to the nature of subatomic particles and their behavior, which is a topic within the realm of Physics, specifically nuclear physics and quantum mechanics. Through extensive investigation using advanced technology such as scanning tunneling microscopes, scientists have discovered that some subatomic particles are unstable and can change into other particles. This process is observed in phenomena like radioactive decay, where atomic nuclei emit particles and transform into different elements or isotopes.
For instance, in radioactive decay processes such as alpha and beta decay, the original nucleus loses particles and becomes a new element. In alpha decay, the nucleus emits two protons and two neutrons (an alpha particle), while in beta decay, a neutron turns into a proton and emits an electron (a beta particle). These examples illustrate how fundamental constituents of matter can undergo transformations that alter their identity.