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Democritus
All about DemocritusDemocritus was born in 460 BC and died in 370 BC. Democritus was the first person to come with an atomic theory. He is credited with discovering the atom. He aslo said all matter came from atoms. He also stated each substance has a different size and shape. -
John Dalton
John DaltonJohn Dalton believed their were also atoms, but he discoverd more about them. He believed they were indivisble and indestructable. He also stated they could be combined to make a compund element. -
Joseph John J.J. Thomspon
Josheph John J.J. ThompsonJ.J. Thompson upported the idea of atoms he discovered smaller particles called subtomic particles. These objects made up the atoms. He also discovered that atoms had positive and negative charges called protons and electrons. he proposed a model that looked similar to a chocolate chip cookie. -
Ernest Rutherford
Ernest discovered that thompsons atomic model was incorrect.He discovered that the positive charges were located in the nucleus. Most of the atom was empty space. -
Neils Bohr
Bohr refined Rutherfords atomic model. Bohr said electrons orbit the nucleus. Electrons wtih low energys orbited closer and the oppisite for high energies., Later james chadwick found the neutron.
