Joseph John Thomson was a British scientist who discovered and identified the electron. Thomson demonstrated in 1897 that cathode rays were actually units of electrical current made up of negatively charged particles of subatomic size. He believed them to be an integral part of all matter and theorized a model of atomic structure in which a quantity of negatively charged electrons was embedded in a sphere of positive electricity, the two charges neutralizing each other. For these investigations, he won the 1906 Nobel Prize for physics; in 1908 he was knighted. Thomson was a gifted teacher—seven of his research assistants as well as his son, George, won Nobel Prizes for physics. He also helped lead Great Britain to dominance in the field of subatomic particles in the early decades of the 20th century. He was honored with burial in Westminster Abbey.

Sources

• Chemical Heritage Foundation (Content Partner); Peter Saundry (Topic Editor). 2008. "Thomson, Joseph John." In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth March 20, 2007; Last revised August 25, 2008; Retrieved October 25, 2009]. <http://www.eoearth.org/article/Thomson,_Joseph_John>