Niels Bohr was born in 1885 in Copenhagen, Denmark. Bohr received his doctorate in physics from the University of Copenhagen in 1911. He then traveled to Manchester, England to study under British physicist Ernest Rutherford. In 1913, Bohr published a theory about the structure of the atom based on an earlier theory of Rutherford's. Rutherford had shown that the atom consisted of a positively charged nucleus, with negatively charged electrons in orbit around it. Bohr expanded upon this theory by proposing that electrons travel only in certain successively larger orbits. He suggested that the outer orbits could hold more electrons than the inner ones, and that these outer orbits determine the atom's chemical properties. Bohr also described the way atoms emit radiation by suggesting that when an electron jumps from an outer orbit to an inner one, that it emits light. Later other physicists expanded his theory into quantum mechanics. This theory explains the structure and actions of complex atoms.
Bohr is best known for the investigations of atomic structure and also for work on radiation, which won him the 1922 Nobel Prize for physics.
Bohr became a professor of physics at the University of Copenhagen in 1916. In 1920, Bohr was named director of the newly constructed Institute of Theoretical Physics at the University, now the Niels Bohr Institute. During the Nazi occupation of Denmark in World War II, Bohr and his family fled Copenhagen to escape arrest by the Nazis. Bohr spent the last two years of the war in England and America, where he became associated with the Atomic Energy Project. In his later years, he devoted his work to the peaceful application of atomic physics and to political problems arising from the development of atomic weapons.
Niels Bohr died in Copenhagen in 1962.
Information as of 1926