History of the Atom Timeline by Xavier Bonnette and Cody Aiken

By boogie55
  • 450

    Aristotle (384-322 B.C.)

    Aristotle (384-322 B.C.)
    Aristotle didn't believe that the atom existed. He believed that everything was made up of fire, air, water, and earth or combinations of the four. He did not use a method; he simply thought of it on his own.
  • 450

    Democritus (400 B.C.)

    Democritus (400 B.C.)
    Democritus said that everything is made upmof atoms. That they can be physically indivisible and are indestrucable. Atoms are constantly moving. Democritus made the forst atom model. He and Leucippus had the same basic work. Democritus simply thought abouth the atom and made models and observations on his own. He thought it looked like a bball or a 3-D circle.

  • Dalton (1766-1844)

    Dalton (1766-1844)
    all matter is made of atoms and are indestructible and indivisible. All atoms of an element are identical in mass and properties. Introduced the compound. A chemical reaction is a rearrangement of atoms. Used Democritus's method.

  • Thomson

    Thomson
    Found out that there are very small negatively charged particles i the atom (electrons). He thought that the atom had more of a definate shape. He was experimenting with the cathode ray when he discovered the electron.

  • Rutherford

    Rutherford
    Discovered that the atom had a nucleus that the protons were in. He changed the previous model by adding a nucleus.To find this out he sent alpha rays through gold foil.

  • Bohr

    Bohr
    Electrons can only orbit at certain allowed distances from the nucleus. Atoms radiate energy when an electron jumps from a higher energy orbit to a lower energy orbit. He changed the previous atom model by putting the electrons on rings seperate from the nucleus.Bohr studied Rutherford's model and perfected it to his idea of what it looked like.

  • Heisenberg and Schrodinger

    Heisenberg and Schrodinger
    They thought that the electrons moved in waves instead of circles around the nucleus. They also changed changed the previous atoms model by having the electrons move in waves. They studied previous versions and improved them to what they thought the atom looked and acted like.

  • Bibliography

    "John Dalton." John Dalton. N.p., n.d. Web. 27 Feb. 2014.
    "A Look Inside the Atom." A Look Inside the Atom. N.p., n.d. Web. 27 Feb. 2014.
    "Atomic Structure Timeline." Atomic Structure Timeline. N.p., n.d. Web. 27 Feb. 2014.
    "Heisenberg - Quantum Mechanics, 1925-1927: The Uncertainty Principle." Heisenberg - Quantum Mechanics, 1925-1927: The Uncertainty Principle. N.p., n.d. Web. 27 Feb. 2014.
    "Erwin Rudolf Josef Alexander Schrödinger." Schrodinger Biography. N.p., n.d. Web. 27 Feb. 2014.