Atomic theories

By jared2012
  • democritus
    400

    democritus

    • All things are composed of invisible tiny particles of matter, which can’t be destroyed.
  • John Dalton

    John Dalton

    • Described tiny indivisible particles called atoms.
    • Atoms can’t be divided or destroyed.
    • Atoms can join together to form molecules.
    • Atoms of one element are all the same.
  • J.J. Thompson

    J.J. Thompson

    • Atoms contain electrons, which have a negative charge.
    • Atoms are solid with electrons and protons randomly placed through them.
  • Ernest Rutherford

    Ernest Rutherford

    • Atoms have a dense nucleus which contains protons, and most of the rest is empty space.
    • Electrons orbit around the nucleus like planets around the sun.
  • Niels Bohr

    Niels Bohr

    • Electrons are arranged in layers or shells around the nucleus.
    • The shells have different energy levels, and electrons fill up the lowest levels first.
  • James Chadwick

    James Chadwick

    • The nucleus also contains neutrons, which are unchanged particles with a similar mass to protons.