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
A Is for Atom A Is for Atom A Is for Atom is a 14-minute 1953 promotional animated short documentary film created by John Sutherland and sponsored by General Electric (GE). It is now in the public domain. The short explains what an atom is, how nuclear energy is released from certain kinds of atoms, the peacetime uses of nuclear power, and the by-products of nuclear fission. It is Sutherland's most-decorated film, having won numerous honors at film festivals. "A is for Atom" was re-released by General Electric in 1964. John Sutherland Studios was contracted by GE to modernize the film. Changes include included