Austrian-born American physicist. He won a 1945 Nobel Prize for work on atomic fissions.
Pauli, Wolfgang (1900-1958), American physicist, born in Vienna, Austria. In 1925 Pauli defined the exclusion principle: Only two electrons can occupy the same energy level simultaneously in an atom. In 1931 he hypothesized the existence of the subatomic elementary particle called the neutrino, a fundamental contribution to the meson theory. Pauli was awarded the 1945 Nobel Prize in physics.
exclusion principle (îk-skl¡´zhen
The principle that two particles of a given type, such as electrons, protons, or neutrons, cannot simultaneously occupy a particular quantum state. Also called Pauli exclusion principle.
Exclusion Principle, in physics and chemistry, fundamental principle stating that two electrons cannot simultaneously occupy the same energy state in an atom. This principle, which explains the regularities of the periodic law, was developed in 1925 by Austrian-American theoretical physicist Wolfgang Pauli.
In the quantum mechanical model of the atom, electrons are limited by four values called quantum numbers that describe the atom mathematically. The principal quantum number defines the principal shell (energy state) of an electron. The angular momentum quantum number describes the magnitude of an electron's angular momentum. The magnetic quantum number describes the magnetic orientation of the orbital plane of an electron. The spin magnetic quantum number designates the electron's spin as counterclockwise or clockwise. Physicists use these quantum numbers to establish the maximum number of electrons permitted in each electron shell of an atom.
The Pauli exclusion principle also applies to free electrons and to protons and neutrons in the nucleus. Particles called fermions obey the exclusion principle, but others called bosons do not.
The Institute for Advanced
Study at Princeton University is established with an initial endowment
of $5 million from department store magnate Louis Bamberger, now 75, and
his sister Mrs. Felix Fuld. Abraham Flexner of 1910 Flexner Report fame
has urged them to charter a new type of institution dedicated to "the usefulness
of useless knowledge"; it will attract such minds as Albert
Einstein, Thorstein Veblen, J. Robert Oppenheimer, Wolfgang Pauli,
Quantum Electrodynamics or Qed, in physics, a set of equations that accounts theoretically for the interactions of electromagnetic radiation with atoms and their electrons. QED appears to underlie the chemical and readily observable behavior of matter and to encompass classic electromagnetic theory. The equations, which explain electromagnetism in terms of the quantum nature of the photon, the carrier of the force, were formulated by British physicist Paul Dirac, German physicist Werner Heisenberg, and Austro-American physicist Wolfgang Pauli in the 1920s and 1930s and were elaborated thereafter.
French physicist Louis Victor de Broglie suggested
in 1924 that because electromagnetic waves
show particle characteristics, particles should also show wave qualities;
physicists later verified this prediction experimentally. The wave concept
led Austrian physicist Erwin Schrödinger to develop an equation that
described the wave behavior of particles and, specifically, of the electron
in the hydrogen atom. Schrödinger showed that no two electrons in
an orbit could be in the same energy state. Called the exclusion principle,
this rule had been established in experiments by Austro-American physicist
Wolfgang Pauli in 1925.
- Wolfgang Pauli