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
Up An' Atom training and practice bombing missions and pumpkin bomb missions against industrial targets in Taira and Hamamatsu, Japan. Capt. Bob Lewis's crew B-9 flew it on a pumpkin bomb mission to Tokushima subsequent to the Hiroshima mission, and Lt.Col. James Hopkins and crew C-14 used it to attack Nagoya with a pumpkin bomb. "Up An' Atom" returned to the United States with the 509th CG in November 1945 to Roswell Army Airfield. From April to August 1946 it was assigned to the Operation Crossroads task force. In August 1949 it became part of the 97th Bomb Group at Biggs Air Force