Atom bomb

History of Atoms

  • 200


    Over 2,500 years ago Democritus suspected that matter had extremely little particles that couldn't be divided. He believed that there were different types of atoms for different types of matter.
  • 300


    Aristotle believed that there wasn't a specific amount of times matter can be divided, He believed that everything was made only of air, fire, earth and water.
  • John Dalton

    John Dalton
    John Dalton noticed that all compounds no matter the size the ratio of elements in a compound are always the same. He iscovered thsat this was because of atoms. The main points Dalton addressed were: all elements are made of atoms ; all atoms of the same element have the same mass; compounds contain atoms of more than one element; and in a perticular compound, atoms of different elements combine in the same way.
  • J.J. Thomson

    J.J. Thomson
    Thomson added more than one thing to he knowledge about atoms. He learned that atoms were made of smaller particles than was originally thought. Thomson also learned that particles in an atom are neutral. He discovered this by placing metal disks on opposite sides of a glasstube and watched to see what happened to the beam when the plates were moved.
  • Hantaro Nagaoka

    Hantaro Nagaoka
    Nagaoka thinks an atom has a nucleus. And that positive and negative charges orbit the nucleus, but cannot prove it.
  • Ernest Rutherford

    Ernest Rutherford
    Proved that every atom has a positive charge in the center which he named a nucleus. This was proved when he learned that not all alpha particles were deflected off gold.
  • Niels Bohr

    Niels Bohr
    Proved that electrons moved in a spherical orbit around a nucleus. He also proved that electrons gain or lose energy when they move between energy levels.
  • Erwin Schrodinger

    Erwin Schrodinger
    Came up with math equations to describe how electrons move in atoms. The work he presented concluded to the Electron Cloud Model.
  • Ernest Marsden

    Ernest Marsden
    He was a student of Rutherford. He is known for his part in helping Rutherford's atomic theroy. HE was the one who noticed that when alpha particles were fired at a gold foil they were deflected back.
  • James Chadwick

    James Chadwick
    Gave proof that neutrons are real. Neutrons have no charge. Nucleui contain neutrons and positively charged protons.
  • Louis de Brogile

    Louis de Brogile
    Suggested that some particles like electrons have some properties of waves.