Here's why:
* Beta Decay: Beta decay is a type of radioactive decay where a neutron in the nucleus transforms into a proton, an electron (the beta particle), and an antineutrino.
* Electron Emission: The electron, being negatively charged, is ejected from the nucleus as a beta particle.
* Nuclear Transformation: This process changes the composition of the nucleus, increasing the atomic number by one (due to the formation of a proton) while leaving the mass number unchanged.
Let me know if you'd like to know more about beta decay or other types of radioactive decay!