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Period: 460 BCE to 460 BCE
Democritus
Greek philosopher - atoms=indivisible, small and hard particles -
Period: 384 BCE to 322 BCE
Aristóteles
Greek philosopher-denied existence of atom -
Period: to
John Dalton
British scientist - elements combined specific proportions. Atoms combined with another one= new substances -
Period: to
Henry Mosley
Organized periodic table -
Period: to
J.J Thompson
British scientist - atoms exist smaller particles. Electron = negative particle -
Period: to
Millikan
American physicist - mass of electron, electrin present in all atoms. -
Period: to
Ernest Rutherford
Atoms = small charged nucleus surrounded by largely empty space. -
Period: to
Neils Bohr
Danish scientist - developed atom of atom, energy levels are discrete -
Period: to
James Chadwick
Neutron = particle
Neutrons = central of atoms