Niels Bohr
Danish Physicist
Contributions to Science
Niels Bohr made contributions to understanding atomic structure and quantum theory.The Bohr model shows the atom as a small, positively charged nucleus surrounded by orbiting electrons. Bohr was the first to discover that electrons travel in separate orbits around the nucleus and that the number of electrons in the outer orbit determines the properties of an element. The chemical element bohrium (Bh), #107 on the Periodic Table, is named after him.
Bohr's concept of complementarity, states that an electron can be viewed in two ways, either as a particle or as a wave, but never both of them at the same time. This concept forms the basis of early quantum theory. It stresses that an experiments results are greatly affected by the measurement tools used to carry them out.