Niels Henrik David Bohr was born in 1805 in Copenh Essay Example For Students

Niels Henrik David Bohr was born in 1805 in Copenh Essay agen. He was the son of a physiologyprofessor, and was educated at the University of Copenhagen, where he earned his doctorate in1911. That same year he went to Cambridge, England, to study nuclear physics under the Britishphysicist Sir Joseph John Thomson, but he soon moved to Manchester to work with anotherBritish physicist, Ernest Rutherford. Bohrs theory of atomic structure won him the Nobel Prize in physics in 1922. It waspublished in papers between 1913 and 1915. His work drew on Rutherfords nuclear model of theatom, in which the atom is seen as a compact nucleus surrounded by a swarm of much lighterelectrons. Bohrs atomic model made use of quantum theory and the Planck constant, which isthe ratio between quantum size and radiation frequency. The model shows that an atom emitselectromagnetic radiation only when an electron in the atom jumps from one quantum level toanother. This model contributed greatly to future developments of theoretical atomic physics. In 1916 Bohr returned to the University of Copenhagen as a professor of physics, and in1920 he was made director of the universitys newly formed Institute for Theoretical Physics. There Bohr developed a theory relating quantum numbers to large systems that follow classicallaws, and made other major contributions to theoretical physics. Bohrs work helped lead to theconcept that electrons exist in shells and that the electrons in the outermost shell determines anatoms chemical properties. In 1939 Bohr convinced physicists at a scientific conference in the United States of theimportance of, Otto Hahns and Fritz Strassmans, experiments. He later demonstrated thaturanium-235 is the particular isotope of uranium that undergoes nuclear fission. Bohr thenreturned to Denmark, where he was forced to remain after the German occupation of the countryin 1940. Eventually, however, he was persuaded to escape to Sweden. From Sweden the Bohrstraveled to England and eventually to the United States, where Bohr joined in the effort todevelop the first atomic bomb, working at Los Alamos, New Mexico, until the first bombsdetonation in 1945. He opposed complete secrecy of the projec t, however, and feared theconsequences of this ominous new development. He desired international control. In 1945 Bohr returned to the University of Copenhagen, where he immediately beganworking to develop peaceful uses for atomic energy. He organized the first Atoms for PeaceConference in Geneva, held in 1955, and two years later he received the first Atoms for PeaceAward. In 1997 the International Union of Pure and Applied Chemistry announced that thechemical element with the atomic number 107 would be given the official name bohrium (Bh), inhonor of Niels Bohr.