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Period: 500 BCE to
History of atomic models
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450 BCE
Presocratic philosophers
Leuccipus and Democritus were the first known in occidental culture who used the notion of atom in their speculations about the composition of matter -
Lavoisiser's law
In chemical transformations matter may change its form or shape, but its mass remains the same. -
Richter's law of reciprocal proportions
The amounts of mass of different substances in chemical reactions are related. -
Proust's law of definite proportions
Elements always form a compound in the same proportions in mass -
Dalton's law of multiple proportions
The ratios between the masses of an element that reacts with a fixed mass of another element to form different compounds are simple whole numbers -
Dalton's New System of Chemical Philosophy
Dalton supposed real different indestructible atoms formed matter -
Cathode rays
Crooke's tubes -
The discovery of the electron
Joseph John Thomson with a cathode rays tube -
Rutherford's gold foil experiment
Atoms seem to be hollow -
Thomson's model of atom
Positive sphere with electrons -
Rutherford's atom
Positive nucleus and electron turning around at long distances -
Boht's atom
Light and matter -
Actual atomic model
Electron are in orbitals
