Niels Henrik David Bohr

Bohr, Niels Henrik David (1885–1962), Danish physicist who proposed a model of the atom in 1913, suggesting that the hydrogen atom consisted of a single electron orbiting around a central proton (the nucleus), and that the electron could carry only certain well-defined quantities of energy. This theory accounted both for the atom's stability and for its characteristic radiation and absorption of energy. In 1927 Bohr proposed the complementarity principle to account for apparent paradoxes in the wave and particle approaches to describing sub-atomic particles. Although he helped develop the atomic bomb, he was always deeply concerned about implications for humanity. In 1922 he received the Nobel Prize in physics.

See also: Atom; Physics.