Atom to the positively charged nucleus by the attraction created from opposite electric charges. If an atom has more or fewer electrons than its atomic number, then it becomes respectively negatively or positively charged as a whole; a charged atom is called an ion. Electrons have been known since the late 19th century, mostly thanks to J.J. Thomson; see history of subatomic physics for details. Protons have a positive charge and a mass 1,836 times that of the electron, at . The number of protons in an atom is called its atomic number. Ernest Rutherford (1919) observed that nitrogen under alpha-particle
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.