Niels Henrik David Bohr (pronounced [nels ˈb̥oɐ̯ˀ] in Danish; 7 October 1885 – 18 November 1962) was a Danish physicist who made fundamental contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. The Bohr's model, the theory that electrons travel in discrete orbits around the atom's nucleus.The shell model of the atom, where the chemical properties of an element are determined by the electrons in the outermost orbit. The correspondence principle, the basic tool of Old quantum theory. The liquid drop model of the atomic nucleus. Identified the isotope of uranium that was responsible for slow-neutron fission - 235U.[6]Much work on the Copenhagen interpretation of quantum mechanics. Te principle of complementarity: that items could be separately analyzed as having several contradictory properties.
Placnk At the turn of the century, physicists did not yet clearly recognize that these and other difficulties in physics were in any way related. The first development that led to the solution of these difficulties was Planck's introduction of the concept of the quantum, as a result of physicists' studies of blackbody radiation during the closing years of the 19th century. (The term blackbody refers to an ideal body or surface that absorbs all radiant energy without any reflection.) A body at a moderately high temperature—a "red heat"—gives off most of its radiation in the low