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Nov 3, 1500
Democritius
Democritus thought that the things in his theory (atoms) were all invisible and exactly alike. He also thought that all matter was made up of atoms and they could not be destroyed or erased. He believed that everything is made of tiny things that never get deleted. -
Aristotle
Aristotle did not believe in the atomic theory and he taught so otherwise. He thought that all materials on Earth were not made of atoms, but of the four elements, Earth, Fire, Water, and Air. He believed all substances were made of small amounts of these four elements of matter. -
John Dalton
The main points of Dalton's atomic theory were: Elements are made of extremely small particles called atoms. Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties. Atoms cannot be subdivided, created, or destroyed. -
Robert Brown
The elements arranged in families, ordered in order of increasing atomic number (the number of protons in the nucleus). Brownian Motion. The jerking movement of microscopic particles only visible under a high powered microscope. It was discovered by the biologist Robert Brown in 1827. -
Albert Einstein
Albert Einstein formulates Special Theory of Relativity.Einstein calculates how the movement of molecules in a liquid can cause the Brownian motion.
