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How Atoms Were Discovered

By chloe_010
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    465BCE - Democritus' Theory

    465BCE - Democritus' Theory
    Democritus was born in Abdera, Greece 460BC. Democritus had a mentor, named Leucippus, who was originally with the Atomic Theory, but then, Democritus took over the theory. The theory discusses the universe was made up of two elements, the Void and the Atoms which makes movement and is existing, that all matter is made up of atoms, they are unbreakable, atoms are solid but remain invisible, atoms are alike, Atoms are different in mass, position, arrangement, size and shape.

  • 1808- John Dalton's Atomic Thoery

    1808- John Dalton's Atomic Thoery
    John Dalton is a Chemist and today, he is known for his wonderful explanation of his Atomic Theory. Dalton believed that: All matters are made up of atoms, They are indivisible and destructable, all atoms with a specific element are alike in mass and their properties. Compounds are made by combinations of two or more different kinds of atoms and a chemical reaction is a rearrangement of atoms.

  • 1897- J.J. Thomson discovery of the Electrons

    1897- J.J. Thomson discovery of the Electrons
    Thomson created a plum pudding model of the atoms to represent the negative and the positive charges. In 1906, Thomson thought the atoms consist a little of electrons and this is equal to the atomic number.

  • 1911- Rutherford Atom Theory (date unknown)

    1911- Rutherford Atom Theory (date unknown)
    Ernest Rutherford was born in 1871, and studies physics. Rutherford discovered the alpha and the beta rays, that were set forth the laws of radioactive decay. He was also the one who studied the alpha particles as hellium nuclei.

  • 1913- Neils Bohr's Atomic Theory (date unknown)

    1913- Neils Bohr's Atomic Theory (date unknown)
    Neils Bohr was a fmous scientist in Physics. Bohr created a model of the atoms. This shows a small, positively charged nucleus surrounded by orbiting electrons. Bohr states electrons can be viewed in two ways, either as a particle or as a wave, but never both at the same time.

  • 1932- James Chadwick's Atomic Theory (date unknown)

    1932- James Chadwick's Atomic Theory (date unknown)
    James Chadwick, was born in Cheshire,England. Chadwick states the existence. Chadwick said that there will be a neutron for each atom, confirmed the atomic number is determined by the numbers of protons in an atom and discovered the fourth subatomic particle,the neutron.