Niels Bohr

(1885 - 1962 AD)

Danish physicist who proposed a successful quantum model of the atom in 1913. His model assumed that (1) the electron exists at precise distances from the nucleus, (2) as long as an electron remains in one location, no energy is given off, (3) electrons have circular orbits (this is only correct for s orbitals), and (4) the angular momenta associated with allowed electron motion are integral multiples of ħ. Bohr stated the Correspondence Principle, which states that quantum mechanical formulas must reduce to the classical results in the limit of large quantum number. He also advocated a probabilistic interpretation of quantum mechanics known as the Copenhagen interpretation.

**The preceding information is provided by the Eric Weisstein's World of Scientific Biogra.**