-
Said everything was composed of atoms. Said atoms can't be split any further. Said atoms are indestructible.
-
Disagreed with Democritus. Believed there were only four elements: air, earth, fire, and water. Said there were no atoms.
-
Presented the first scientific classification of minerals.
-
Wrote a book that overturned Aristotle's concept of the four elements.
-
Developed Law of Conservation of Mass. Recognized and named Oxygen and Hydrogen. Opposed the Phlogiston Theory.
-
Developed Law of Definite Proportions.
-
Proposed that elements consisted of atoms that were identical and had the same mass and that compounds were atoms from different elements combined together.
-
Developed the Law of Combining Volumes.
-
Developed Avogadro’s law.
-
J.J. Thomson discovered the first subatomic particle (the electron).
-
Realized that some invisible radiation had been emitted from the uranium.
-
Discovered that electrons charge is negative. Used the oil drop experiment.
-
Created the Bohr model of the atom.
-
Discovered that the nucleus was surrounded by a void before the cloud of electrons.
-
Originator of the quantum theory of energy.
-
Discovered the wave nature of electrons and suggested that all matter have wave properties.
-
Created the theory of quantum mechanics.
-
Created the quantum mechanical model of the atom.
