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Said matter is all around us, (Plato also attacked Democritus on his contribution of the atomic theory) -
Democritus said all atoms constantly move, and that all atoms were solid, hard, uniform in shape, and indestructible, (He was a student of Leucippus) -
Leucippus (A Greek philosopher) believed some type of particle were constantly moving and creating matter through natural laws -
He thought everything is composed of tiny particles. (He also was an alchemist like Leucippus) -
He believed matter was composed of atoms that were not created or destroyed during chemical reactions. (He also said a total mass of compounds were a total mass of individual elements) -
Dalton's model of an atom and thought atoms as solid spheres could not be broken in to smaller parts -
Discovered all matter is made of atoms and that atoms of the same element are exactly the same (He also invented the Billard Ball Model.) -
Discovered equal volumes of gases under the same temperature and pressure will contain equal number of molecules. (Also he discovered that elementary gases like hydrogen, nitrogen, and oxygen are composed of two atoms.) -
He discovered elements are arranged according to their value of atomic weight. (He also made the periodic table.) -
discovered electrons (He also conducted the Cathode Ray tube experiment and made the Plum Pudding Model) -
Discovered Radioactivity originated within atoms themselves. ( They also discovered Radioactivity) -
J.J. Thomson's model depicts the electron as negative charged particles embedded in a sea of positive change. -
Discovered atoms are made of smaller subatomic particles. (He also said all liquid is made up of molecules.) -
He discovered electrons have fixed, measurable charge. (he also found the charge to mass ratio of an electron) -
discovered the mass of the atom is concentrated in its nucleus (also discovered atoms are mostly empty space) -
Discovered that electrons travel in definite paths.( He also discovered electrons jump between levels from path to path.) -
Bohr's model describes atoms as consisting of a nucleus with a number of electrons in orbit around the nucleus -
Discovered atomic number is determined by the atomic number. ( He also worked in Radioactivity research and worked on the X-ray spectra in the elements) -
He discovered that electron paths cannot be predicted. (He also said electrons are found in electrons are found in electron clouds instead of paths) -
Heisenberg and Schrodinger's model that represents the area around an nucleus where electrons are likely to be found -
He discovered the neutron.(He also worked to build the atomic bomb and also won a Nobel Prize)