Caption:
Niels Bohr (1885-1962), Danish physicist. Bohr won the Nobel Prize for Physics in 1922. He developed the quantum theory of electron orbitals, which stated that electrons could only occupy specific regions around an atomic nucleus. His model fit very well with the observed spectrum of hydrogen. He also applied quantum theory to atomic nuclei, and with Wheeler predicted that uranium-235 would be the best isotope for fission (and thus a bomb).