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400 BCE
Democritus (Greek philosophe)
he was the first person to use the term atom, in his most important conclusions he said: all matter consists of atoms and that atoms are completely solid -
John Dalton
He was the first to adapt Democritus' theory into the first modern atomic model. said atoms are indestructible or unchangeable -
J.J Thomson
was the philosopher who is credited with discovering the electron. stated that the charge is invisible and a fluorescent screen is required to view it -
Thomson's Atomic Model
Thomson predicted what an atom would look like: due to its design. said that electrons are particles with suspended negative charges -
Ernest Rutherford
He was not convinced about the model of the atom proposed by Thomson. He said there must be a positive center of the foil. he called this nucleus -
Rutherford's Atomic model. Aka planetary model
Rutherford state that the atom was like a mini solar system and that the electrons orbited the necleus in a wide orbit. That is why is known as THE PLANETARY MODEL -
Niels Bohr. Atomic model (aka the Rutherford-bohr model)
Using is knowledge of the energy and quantum physics he was able to perfect Rutherford's model.
He said that the lower the energy the electron the smaller the orbit will be. this means that as the electrons fill the orbits they will fill the lowest energy level first -
Erwin Eschrodinger
He arrived at the atomic model that we still use today, said that the electron does not travel in a specific orbit, and we cannot say for sure where it is or where it should be.
