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originated when the Aristotle took up an old idea which was that all matter combined was the 4 elements fire, water, air, earth. -
he believed that atoms were uniform solid, hard, in-compressed and indestructible and moved in infinite numbers through empty space -
plato postulated a fifth atomic type must exist which Aristotle later called ether. -
Nicolas compernicus -
said elements could not be broken down and can use experiments to break it down -
father of modern chemistry gave an element its name determined oxygen was an essence substance. -
john dalton -
Introduced the atomic theory and law of conservation to chemistry -
found out that when all the known chemical elements were arranged in order of increasing atomic weight. -
Experiments with blue ray tubs shown that all atoms contain tiny negatively charged subatomic particles or electrons. -
Discovered the strongly radioactive elements polonium and radium which occurs naturally in uranium minerals -
jj Thomson -
developed the theory of relativity also quantum mechanics proved existence of atoms mathematically. -
he discover that there was a fundamental electric charge of an electron his gold foil showed that atoms have a small dense positively charged nucleus. -
found out the atom was mostly empty space and all of the mass is centered in the middle in the nucleus which is the positively charged and surrounded by negative charged electrons. -
he contributed to the structure and quantum theory received nobel pice prize. -
used self built equipment to prove major properties of an elements were determined by the atomic number. -
erwin schrodinger -
he bombarded beryllium atoms with alpha particles an unknown radiation was produced -
quantizations of the atoms energy levels that appear in Neil's Bohrs atomic model could be calculated bay the Schrodinger equation