Helium atom 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 wavefunction of the atom. The quantum mechanical description of the helium atom is of special interest, because
Captain Atom of alternate Captains Atom, including Earth-13's Brigadier, the Captain Atom as depicted in the graphic novel "Kingdom Come" (Earth-22), and a Captain in a red/silver variant of the Monarch's costume, one similar to the Charlton Comics Atom (Earth-4), and a Hulked out variant named Attum from an unknown Earth. Several more variants are shown in "Countdown: Arena" #4, including a President Atom, a robot called Quantum Mechanix, Kid Quantum of the Legion of Super-Heroes, Captain Adamma, Quantum Boy, an anthropomorphic wolf version, a from Earth-30, a Doctor Manhattan-lookalike, an energy based-Atom who makes calculations during his attacks, and a giant-sized