Atom with electrons

Science Contributions

  • John Dalton

    John Dalton
    Experiment: 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 Stoney

    G. Johnstone Stoney His contrbution was the fundamental unit of electricity.
  • J. J. Thombson

    J. J. Thombson
    Experiment: 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 Rutherford

    Ernest Rutherford
    Experiment: 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 Bohr

    Niels Bohr
    Experiment 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 Rutherford

    Ernest Rutherford Contribution was the charge and mass of the proton.
  • James Chadwick

    James Chadwick
    Experiment: Found that this beam was deflected by electric or magnetic fields.
    Conclusion: The particles carried no electric charge
    Contribution: Neutral neutrons
  • Murray Gell-Mann

    Murray Gell-Mann
    Experiment: 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 Perl

    Martin Perl His contribution was the leptons