Helium atom −54.41776311(2) eV. The total ground state energy of the helium atom is −79.005151042(40) eV, or −2.90338583(13) a.u. Helium atom A helium atom is an atom of the chemical element helium. Helium is composed of two electrons bound by the electromagnetic force to a nucleus containing two protons along with either one or two neutrons, depending on the isotope, held together by the strong force. Unlike for hydrogen, a closed-form solution to the Schrödinger equation for the helium atom has not been found. However, various approximations, such as the Hartree–Fock method, can be used to estimate the ground state energy and
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