Hydrogen atom Hydrogen atom A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force. Atomic hydrogen constitutes about 75% of the baryonic mass of the universe. In everyday life on Earth, isolated hydrogen atoms (called "atomic hydrogen") are extremely rare. Instead, hydrogen tends to combine with other atoms in compounds, or with itself to form ordinary (diatomic) hydrogen gas, H. "Atomic hydrogen" and "hydrogen atom" in ordinary English use have overlapping, yet distinct, meanings. For example, a
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