Why do ratioactive isotopes emit radiation?
Whatever atoms do is to get rid of energy. Atoms are low key, and like to have as little extra energy as possible. Chemistry deals with how atoms lower their energy by forming chemical bonds and releasing electromagnetic radiation (like x-rays and visible light). Nuclear physics deals with how atoms lower their energy by emitting radiation and possibly changing protons to neutrons and vise verse. Most questions regarding why atoms do things is all about having less energy. If an electron is too far away from the nucleus, bring it closer and emit electromagnetic rays. If there is too much junk in the nucleus, toss it out as radiation.
