History of the Atom Timeline by Bailee Weston

By baileeweston
  • 450

    Democritus (400 BC)

    Democritus (400 BC)
    WHAT HE DISCOVERED:
    He said that everything is made up of atoms, and bewteen atoms lies empty space. There are an infinite amount of atoms and and all atoms differ in shape and size based on what material they make up.
    METHODS HE USED:
    The came up with theories through several expirements. He used his five senses to relate to atoms. He believed taste was based on the texture of the atom. Coffey, Jerry. "Democritus Atom." Universe Today RSS. N.p., n.d. Web. 26 Feb. 2014.
  • 450

    Arisotle (340 BC)

    Arisotle (340 BC)
    WHAT HE DISCOVERED:
    Matter must be made of smaller pieces becasue things can continuously be broken down. He also believed that all things were made up of four elements: earth, fire, water, and air.
    METHODS HE USED:
    Aristotle used mathmatical models he studied from Plato and biology observations of the earth. Harvey, Nicole. "Atomic Theory Powerpoint." Atomic Theory. Lecture. Aristotles Atom Model." Aristotles Atom. N.p., n.d. Web. 27, Feb. 27

  • Dalton

    Dalton
    WHAT HE DISCOVERED:
    All matter is made up of atoms. Atoms of the same element have identical properties and believed that atoms were indestructible. Dalton discovered that a combination of two or more of different atoms create an element, and a chemical reaction is a rearrangement of atoms.
    METHODS HE USED:
    He used mathmatical models to discover that atoms of he same element are identical. Harvey, Nicole. "Atomic Theory Powerpoint." Atomic Theory. Lecture.
    "Niel Bohr's Model." N.p., n.d.Web"

  • Thompon

    Thompon
    DISCOVERY:
    He discovered elcectrons using the "Cathode Ray Tube" which measured electrical charges. He also discovered that atoms are large bodies of positive charge with negative parts dispersed thoughout the atom.
    METHODS:
    Named this series of three expirements the "Cathode Ray Tube." WIth this he caught adn measured electrical charges. BUt he couldnt serperate the chagres from the rays.
    His model is the "Plum Pudding Model" Harvey, Nicole. "Atomic Theory Powerpoint." Atomic Theory. Lecture.
  • Period: to

    HIstory of the Atom

  • Rutherford

    Rutherford
    DISCOVERY:
    He discovered that every atoms has a tiny nucleus, but that nucleus contains 99% of the atom's mass. The nucleus has an overall positive charge.Atoms are not always stable.
    METHOD:
    He performed the "Gold Foil Experiment." He shot particles onto a piece of gold foil. Few particles bounced back; most of the particles passed through the foil.
    His atom model is called the "Nuclear Model." Harvey, Nicole. "Atomic Theory Powerpoint." Atomic Theory. Lecture.

  • Bohr

    Bohr
    WHAT HE DISCOVERED:
    He expanded on Rutherford's theory. He discovered that protons are in the nucleus and electrons surroundthe nucleus. Those electrons move in certain paths around the nucleus and the outer-most electrons determine that elements chemical property.
    METHODS:
    He used evidence from expirements. He took his data and created the Bohr Diagram which shows the number of electrons in each energy level. Harvey, Nicole. "Atomic Theory Powerpoint." Atomic Theory. Lecture.

  • Heisenberg and Schrodinger

    Heisenberg and Schrodinger
    DISCOVERY:
    They discovered the electrons are in a cloud around the nucleus. This cloud is casued by the fast motion of the electrons. He also hypothesized that no one can ever know an electron's location or speed.
    METHOD:
    He gathered evidence from expirements. He used light rays to strike the particle and the rays bounced back through the microscope to the eye. Harvey, Nicole. "Atomic Theory Powerpoint."
    "Erwin Schrödinger." Erwin Schrödinger - Biographical. N.p., n.d. Web. 27 Feb. 2014.