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 Mister Atom Mister Atom is a fictional comic book supervillain, a radioactive robot who is regularly seen as an enemy of Captain Marvel. Mister Atom first appeared in "Captain Marvel Adventures" #78 and was created by Otto Binder and C. C. Beck. Mister Atom was created by Dr. Charles Langley in a story in "Captain Marvel Adventures" #78. His body was constructed first, and then Langley charged the robot with radioactive energy. The spark that gave the robot life also ended the life of his creator. Super-charged with a nuclear reactor and armed with a deadly mind, Mister Atom went