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460 BCE
Democritus
Democritus’s model stated that matter consists of invisible particles called atoms and a void (empty space). He stated that atoms are indestructible and unchangeable. Also that they are homogenous, meaning they have no internal structure. His atomic model was solid, and stated all atoms differ in size, shape, mass, position and arrangement, with a void exists between them. -
John Dalton
Dalton's Gas Laws: Dalton came up with his theory of atoms as a result of his research into gases.https://youtu.be/thnDxFdkzZs -
J. J. Thompson
J. J. Thompson was an English scientist, he discovered the electron when he was experimenting with gas discharge tubes. When he saw a movement in the tubes he called it cathode rays. The rays moved from the negative end of the tube to the positive. -
Lord Ernest Rutherford
Physicist Ernest Rutherford established the nuclear theory of the atom with his gold-foil experiment. When he shot a beam of alpha particles at a sheet of gold foil, a few of the particles were deflected. He concluded that a tiny, dense nucleus was causing the deflections. -
Niels Bohr
Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another.
