What The People Did and How Flashcards
Democritus
Original discovery of the atom. If you cut something up small enough, there has to eventually be an uncuttable piece.
John Dalton
All elements are made of invisible particles also known as atoms. He found this out by doing the combination of pure gases into liquids and through this also discovered the molecule.
J. J. Thomson
Discovered electrons, mass of electrons, and ions. Discovered this by using a cathode ray tube which meant he was able to observe electricity jumping through seemingly empty space. He also was able to bend the phosfluorescent gas in the vacuum with a magnet. He thus deduced the electron and its charge. Plum pudding model.
Ernest Rutherford
Through the gold foil and alpha particle experiment, Ernest discovered the nucleus. Added to Thomson’s model.
James Chadwick
Theorized and discovered the neutron by recognizing that because electrons have no weight and protons only account for half of the mass of the whole atom, there must be a neutrally charged particle in the nucleus which is about the same weight as the proton.
Niels Bohr
Discovered the planetary model of the atom as well as the recognition that electrons can appear somewhere else i.e. the next highest energy level if instantly charged with enough energy.
Wolfgang Pauli
Discovered the exclusion principle which basically states that there may only be two electrons on one orbit.
Maria Goeppert-Mayer
She discovered the nuclear shell theory that the most stable of atoms have 2, 8, 28, 50, 82, or 126 protons or neutrons on one orbit within a given nuclei.
Murray Gell Mann
This man discovered the quark which is the currently known fundamental structure particles of matter. He smashed atoms together and say what came out of collisions involving protons and neutrons. He was then able to discover what he called the quark.
