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400
Democritus
He found that all matter consists of invisible particles called atoms. Also that atoms are indestructible and atoms are solid but invisible. Another thing he discovered toms are homogenous and that atoms differ in size, shape, mass, position, and arrangement. 400 B.C. -
John Dalton
He discovered that all elements are made of atoms. He developed helped further the idea atom and made the atom idea useful and accepted by many people. Dalton’s atomic theory defined the relationship between atoms and elements. -
JJ Thomson
Thompson found that atoms were not simple spheres. He discovered electron, which create electricity. He found that electrons were negatively charged. -
Albert Einstein
He published the E=mc2 equation, which is energy = mass energy equivalence. -
Ernest Rutherford
He found that atoms were mostly mad of space. He also discovered the nucleus and gave it its name. Also that positively charged subatomic particles were all located inside the nucleus and all the negatively charged particles are located outside of it and around the perimeter of the atom. -
Neils Bohr
Bohr proposed that electrons orbited around the nucleus. He stated that each electron had fixed energy and orbit around in fixed energy levels. The farther away from the nucleus, the level is the more energy the electron contains. -
Erwin Schrodinger
Schrödinger used mathematical equations to describe the likelihood of finding an electron in a certain position. This atomic model is known as the quantum mechanical model of the atom. Unlike the Bohr model, the quantum mechanical model does not define the exact path of an electron, but rather, predicts the odds of the location of the electron. This model can be portrayed as a nucleus surrounded by an electron cloud. Where the cloud is most dense, the probability of finding the electron is grea -
Werner Heisenberg
He developed a model of proton/neutron interaction; he discovered more info on the nucleus.