The subatomic particle that never changes is the electron. Electrons are fundamental particles that carry a negative electric charge. They are considered to be elementary particles, meaning they are not made up of smaller components. Unlike protons and neutrons, which can undergo changes in certain nuclear reactions, electrons remain stable and do not change under normal circumstances.
Electrons play a crucial role in chemical reactions and the formation of chemical bonds. They are also essential in the field of electronics, where their movement generates electric current. The stability and unchanging nature of electrons make them a fundamental building block of matter.