History of Atomic Theory
By nikko1301, Updated
The history of the Atomic Theory including who discovered what, when and how.
Democritus: 490BC+: Atoms exist
The universe is composed of two elements. Atom, and the void in which they exist and move.
Atoms are indivisible, atoms of a certain element are identical and compound are a mixture of different types of atoms.
Jon Dalton: 1803: Solid Sphere Model
Discovered Electrons and created the Plum Pudding Model which composes that atoms are scattered electrons throughout a spherical positive charge.
Joseph.John. Thompson: 1904: Plum Pudding Model
Ernest Rutherford: 1911: Nuclear Model
Atoms are mostly empty space with a positive charge concentrated in the centre-the nucleus.
Modified Rutherfords model, electrons move around the neutron in orbits of fixed size and energies-this model quantised the electrons energy. Electrons could not occupy values of energy between the fixed energy level according to this model.
Niels Bohr: 1913: Planetary Model
Electrons do not move in set paths around the nucleus, but rather in waves. It is impossible to know the exact location of an electron, instead there are clouds of probability called orbitals in which we are more likely to find an.
Erwin Schödinger: 1926: Quantum Model
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