Atom the nucleus defines to what chemical element the atom belongs: for example, all copper atoms contain 29 protons. The number of neutrons defines the isotope of the element. The number of electrons influences the magnetic properties of an atom. Atoms can attach to one or more other atoms by chemical bonds to form chemical compounds such as molecules. The ability of atoms to associate and dissociate is responsible for most of the physical changes observed in nature and is the subject of the discipline of chemistry. The idea that matter is made up of discrete units is a very old
Mister Atom long, however: In "52", Captain Marvel mentioned that Mister Atom attacked the Rock of Eternity, only to fail. It is later revealed that Mister Atom is one of the villains who helped Prometheus plant explosive devices in various cities across the U.S., which leads to Mister Atom and several other villains making an attempt to flee the country. Before they can cross the border, the group is attacked by the Justice League, and Mister Atom is defeated and captured by Starman and Congorilla. Mister Atom has upper level superhuman strength and endurance. His robot body is virtually impervious to harm.