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460
Democritus
He was an Ancient Greek Philosopher who claimed that everything was made up of atoms. These atoms where physically inseperable and indestructable. Inbetween them lies empty space but the atoms will always be in constant motion. He also said that theirs a fathomless amount of atoms which differ in size and shape. About the mass of atoms, he said, "The more any indivisible exceeds, the heavier it is." He declared that the solidness of a material is due to the shape of the atoms involved. -
Period: 460 to
Atom Timespan
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John Dalton
John Dalton was an English chemist that proposed an atom theory. His theory was that all matter is made of indestructable and indivisble atoms--very much like Democritus' theory; all atoms in a given element are identical in properties and mass; compunds are configurated by two or more different atoms; a chemical reaction is the reposition of atoms. -
Thomson
Thomsons atom theory proposed that; an atom consists of a sphere thats positive charged with negative charged electrons implanted in it; an atom has no over all positive or negative charge, instead the positive and negative charges are equal in magnitute because the atom is electrically neutral. -
Rutherford
Rutherford is well-known as the 'father of nuclear physics.'
He named the Aplha and Beta particles and proton. He did a gold foil experiment to showcase that the atom has a tiny nucleas. -
Bohr
Bohr made a conrtibution to modern physics with his theory. His model showcased his theory. His model was of an atom with a positively charged nulceas surrounded by orbiting electrons. Bohr discovered that electrons orbit separatly around the nucleas. He also discovered that the number of electrons on the outer orbit determines the properties of that element. -
Chadwick
James Chadwhick discovered that nuetrons were apart of the structure of an atom. Nuetrons stabalize the atom and are located in the nucleas.
