Niels Bohr
Niels Bohr was born in Copenhagen, he is the son of a physiology
professor, and
went to school at the University of Copenhagen, this is where
he got his
doctorate in 1911. Bohr won the Nobel piece prize for his theory
of atomic
structures. According to Microsoft Encarta His work drew on
Rutherford’s
nuclear model of the atom, in which the atom is seen as a
compact nucleus
surrounded by a swarm of much lighter electrons. He thought
that electrons are
arranged in definite shells, or quantum levels, at a big
distance from the
nucleus. The arrangement of these electrons is called the
electron
configuration. The number of these electrons equals the atomic
number if the
atom; hydrogen has a single electron, helium has 2, and uranium
has 92. The
electron shells are built from a first shell to a total of seven
shells. The
first shell is complete with two electrons, the second can hold
up to eight
electrons, and the following shells hold larger numbers. The last
electrons
determine the chemical behavior of the atom.