Atomic discoveries

  • Democritus Theory
    400

    Democritus Theory

    He thought that all matter is composed of tiny indestructible units, called atoms. he thought atoms in liquids were round and smooth,and solids were rough and prickly.
  • Daltons theroy

    Daltons theroy

    All elements are composed of atoms. All atoms of the same element have the same mass, and atoms of different elements have different masses. Compounds contain atoms of more than one element. In a particular compound, atoms of different elements always combine in the same way.
  • Nagaoka Planetary Model

    Nagaoka Planetary Model

    Nagaoka's model said the stability came from rings like the ones of Saturn. The model made two predictions: 1) a very massive nucleus with electrons revolving around the nucleus. 2) This was bound by electrostatic forces like gravity.
  • Thompson's Gold Foil

    Thompson's Gold Foil

    He said that electrons were in a cloud around the nucleus
  • Rutherford's Discovery

    Rutherford's Discovery

    He proved that most of an atom's mass was in the center (nucleus) of an atom. This was different from Thompson's.
  • Chadwick Discovers Neutron

    Chadwick Discovers Neutron

    Chadwick discovered that there were smaller particles in the nucleus of an atom. These he called neutrons.