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101
Democritus - 429 BC
First person to think of the atom
Thought atom was a solid sphere -
101
Aristotle - 400 BC
Everything is made up of 4 elements.
They are earth, air, fire, and water -
Isaac Newton
He believe that there were tiny pieces swimming. (Atoms) -
John Dalton
True- All matter is composed of atoms. Different elements have different typees of atoms. Compounds are from atoms of different atoms. Chemical reactions occur when atoms rearranged`
False- All atoms of same elements are identical. Atoms cannot be made or destoryed. -
Henri Becquerel
helped discover radioactivity -
JJ Thompson
Proved the existence of electrons -
Robert Millikan
meausred change and mass of electron -
Rutherford
Proved nucleus was in the middle. -
Neils Bohr
Electrons travel in circular orbits. -
Francis Aston
discovering of isotopes of non radioactive element -
Erwin Schrodinger
discovred formula that calcualtes the odd of electron might be -
James Chadwick
discovered the nuetron