Kids discover incredible power stored inside the tiny atom! The key concept is that huge amounts of energy can be released when the forces that hold the nucleus of an atom together are disturbed. That can happen through fission, the splitting of an atom's nucleus, or fusion, the combining of protons and neutrons from two different atoms. Pioneering scientists Lise Meitner and Marie Curie are introduced, and students learn how their research led to a greater understanding of the atom. Kids also learn that although nuclear energy is a clean, almost inexhaustible energy resource, there are safety issues that must be addressed.