History of the Atom

Timeline created by Ryan.Petro
  • John Dalton "Solid Sphere Model"

    His theory stated that atoms were indivisible, those of a given element are identical, and compounds are combination of different types of atoms.
  • J.J. Thomson "Plum Pudding Model"

    Discovered electrons in the atom. Produced the 'plum pudding' model of the atom. It shows the atoms as composed of electrons scattered throughout a spherical cloud of positive charge.
  • Ernest Rutherford "Nuclear Model"

    Fired positively charged alpha particles at a thin sheet of gold foil. Most passed through with little deflection, but some deflected at large angles. Concluded that the atom was mostly empty space with a positively charged center (the nucleus).
  • Niels Bohr "Planetary Model"

    Modified Rutherford's model of the atom by stating that electrons moved around the nucleus in orbits of fixed sizes and energies. Electron energy in this model was quantized; electrons could not occupy values of energy between the fixed energy levels.
  • Erwin Schrodinger "Quantum Model"

    Stated that electrons do not move in set paths around the nucleus but in waves. It is impossible to know the exact location of the electrons, instead, we have 'clouds of probability' called orbitals, in which we are more likely to find an electron.