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450 BCE
Democritus
Democritus came up with the idea of atoms. He had a hypothesis that if he cut up an apple into smaller prices there would be a point where it can't be cut no more. Making it so small that it's uncuttable and called them atoms. -
John Dalton
John Dalton experimented Democritus idea of atoms. He experimented the pressure of gas to discover that's it's consisted of tiny gas particles. His theory was that all substances are made of atoms and if the atoms are of the same element they are the same mass. -
JJ Thomson
JJ Thomson discovered electrons. By experimenting the electric current through a vacuum tube he came up with the idea of electric currents being negative rays rather than positive. He proved that negative particles are a part of atoms aswell. -
Ernest Rutherford
In 1899 Ernest Ruthford discovered the nucleus. He discovered that all the positive charge came from the center of the nucleus and later discovered the nucleus had positive particles called protons. He failed to prove his hypothesis of neutrons correct but one of the students that are discovered them in 1932. His model proved Thomson's plum model was wrong by showing that positive charge isnt spread out but instead in the nucleus and the rest is empty space with electrons orbiting it. -
Neils Bohr
Neils Bohr came up with a diagram showing electrons don't radiate energy as they orbit but it instead have stationary states and orbit at fix distances
