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460 BCE
Democritus
He discovered that all matter is made of invisible things called atoms. -
Antoine Lavoisier
He named the elements carbon, hydrogen, and oxygen, and discovered oxygen’s role in helping us breath. He also discovered that water is made of hydrogen and oxygen. He also discovered sulfur, He confirmed that matter can not be created nor destroyed. -
John Dalton
Dalton discovered that the forces thought to cause pressure only worked between atoms of the same type -
Eugene Goldstein
Eugene Goldstein discovered protons. -
J. J. Thomson
He discovered that all atoms contain have electrons. -
Henri Becquerel
He discovered radioactivity. -
Electron discovery
J.J. Thomson experimented with ray tubes and it revealed that all atoms contain tiny negatively charged particles. -
Max Planck
He discovered the relationship between energy and the radiation frequency. -
Robert Millikan
Robert Millikan discovered the magnitude of an electron's charge. -
NIels Bohr
He created a model of an atom where the electron was able to go into orbits around the nucleus. -
Ernest Rutherford
Rutherford created the theory that atoms have a nucleus with protons and neutrons in it. -
Proton discovery
Ernest Rutherford discovered the proton by electrocuting hydrogen gas while using gold foil. -
Louis de Broglie
He discovered that the electron was in a wave shape. -
Werner Heisenberg
He discovered the probabilistic characteristics of electrons. -
Erwin Schrödinger
He made an equation that calculated the energy levels of electrons in atoms. E ( n ) = − 1 n 2 × 13.6 e V -
Neutron discovery
James Chadwick discovered neutrons by using the Rutherford gold foil experiment. -
James Chadwick
James Chadwick showed that there was a neutral particle with the same mass as a proton.