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History of the Atom Timeline by Sheyane and Aimee

By sheyane10
  • 350

    Aristotle BC

    Aristotle BC
    He believed all matter was made of the four elements and that if you broke matter down, you would still get matter because matter is neither created or destructable. He found this out without proof because people followed him either way because he was such a believed and respected person in society
    Bibliography: "Aristotle’s Contribution | Atomic Model History." Atomic Model History. WordPress, n.d. Web. 03 Mar. 2014. http://atomicmodelhistory.wordpress.com/2010/11/27/aristotles-contribution/.
  • 350

    Aristotle Photo Bibliography

    N/A. N.d. Photograph. Science Blogs. Ethan. Web.
  • 460

    Democritus BC

    Democritus BC
    He said that atoms were small, invisible and hard particles that matter was made of. They're indestructable, filled the space and they were in entirely and were infinite in number. He used theories from observations.
    Bibliography: Walker, Jim. "History of Atoms." History of Atoms. N.p., Sept. 1988. Web. 26 Feb. 2014.
    Democritus. N.d. Photograph. The History of The Atom. Web. 28 Feb. 2014.

  • Dalton

    Dalton
    He reintroduced the atomic theory with the idea that matter was made of tiny particles called atoms that can neither be created or destroyed. He backed this up with the law of mas conversation, constant composition and multiple proportions.
    "A Brief History of Modern Atomic Theory." Chemistry Tutorial : History of Atomic Theory. Ausetute, n.d. Web. 05 Mar2014. http://ausetute.com.au/atomichist.html.
    Photo: Chemistry Project Dalton's Atomic Model. N.d. Photograph. Glogster. Glogster Inc. Web.

  • Thomson

    Thomson
    He discovered the electron and refutted other models by saying the atom was not indivisible but had other parts - electrons and protons. He used cathode ray tubes to do experiments that showed positive and negative charges reacted differently.
    "A Brief History of Modern Atomic Theory." Chemistry Tutorial : History of Atomic Theory. Ausetute, n.d. Web. 05 Mar. 2014. http://ausetute.com.au/atomichist.html.
    Photo: JJ Thomson's "Plum Pudding" Model. N.d. Photograph. IUN. Prof. N. De Leon. Web.

  • Rutherford

    Rutherford
    He concluded that most of the mass in an atom was a small, positively charged nucleus and the number of protons were equal to the number of electrons by a gold foil experiment using positively charged particles.
    "A Brief History of Modern Atomic Theory." Chemistry Tutorial : History of Atomic Theory. Ausetute, n.d. Web. 05 Mar. 2014. http://ausetute.com.au/atomichist.html
    Photo: Rutherford's Atom. N.d. Photograph. IUN. Prof. N. De Leon. Web.

  • Bohr

    Bohr
    He made the planetary model of the hydrogen atom. It showed that electrons move around in orbits with constant energy, they can absorb and gain energy and move at a fast rate, but they can only exist at a discrete level of energy. He worked with another scientist to prove this.
    "A Brief History of Modern Atomic Theory." Chemistry Tutorial : History of Atomic Theory. Ausetute, n.d. Web. 05 Mar. 2014. http://ausetute.com.au/atomichist.html.
    Photo: N/A. N.d. Photograph. Science Blogs. Ethan. Web.

  • Heisenberg

    Heisenberg
    He concluded that you can determine the position of particles and the momentum of the particles, but not both. He used mathmatical equations and models to find this out.
    "History of Atoms." History of Atoms. No Beliefs, n.d. Web. 06 Mar. 2014.
    Photo: Werner Heisenberg. N.d. Photograph. The History of the Atom. Wikispaces. Web.

  • Schrodinger

    Schrodinger
    He found that positively charged nucleus is surrounded by negatively charged electrons and it vibrates in a circle. By making his own mathmatical equations and models, he found this out.
    "History of Atoms." History of Atoms. No Beliefs, n.d. Web. 06 Mar. 2014.
    Photo: Atomic Model. N.d. Photograph. Schrodinger's Model. Tangient LLC. Web.