John DaltonExperiment: Mixtures of gases to determine what properties effect the individual gases had on the properties of the mixture as a whole
Conclusion: Matter is made of atoms, they are identicle, cannot be destroyed or rearranged
Contribution: The Modern Atomic Theory
G. Johnstone Stoneyhttp://schools-wikipedia.org/wp/e/Electron.htm His contrbution was the fundamental unit of electricity.
J. J. ThombsonExperiment: Pumped air out of a glass tube then applied voltage to two metal plates, called electrons, which were placed at either ends of the tube.
Conclusion: A glowing beam struck the walls
Contribution: charge/mass of electron
Ernest RutherfordExperiment: Alpha particles were shot into gold foil that an atom with a nucleus made of protons and neutrons have electrons moving around the nucleus in some way.
Conclusion: The center of the atom is positive and atoms also contain empty space around the center.
Contribution: Positively charged nucleus
Niels BohrExperiment and Conclusion: Examining the Balmer formula, Bohr suggested that atoms could exist (even briefly) only in certain energy levels, and light was emitted only when an atom descended from some higher energy level to a lower one.
Contribution: Energy levels
Ernest Rutherfordhttp://physics.about.com/od/glossary/g/proton.htm Contribution was the charge and mass of the proton.
James ChadwickExperiment: Found that this beam was deflected by electric or magnetic fields.
Conclusion: The particles carried no electric charge
Contribution: Neutral neutrons
Murray Gell-MannExperiment: Deep inelastic scattering which is a process used to probe the insides of an atom
Conclusion: He discovered the differnent flavors of quarks.
Contribution: Quarks (an elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons)
Martin Perlhttp://www.bookrags.com/biography/martin-l-perl-wsd/ His contribution was the leptons