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John Dalton
Dalton expanded on Democritus' theory on the atom by turning it into a scientific theory. Dalton discovered this by studying the ratios in which elements can combine in chemical reaction. Another event that happened was Ohio became the 13th state. -
Period: to
Who Discovered It?
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J.J. Thomson
J.J. Thomson discovered the electron. He used an experiment that passed an electric current through a gas at a low pressure. He then put the gas in a glass tube with metal ends. After doing this he discovered negative plates repeled the energy while positive plates attracted it. The negative ones were called electrons. Another event is San Diego State University is founded. -
Ernest Rutherford
Ernest Rutherford wanted to test the plum pudding method, so he made the gold-foil experiment. He discovered that alpha particles went straight through the foil but some bounced off. Rutherford proposed the atom was mainly space and the positive charged atoms were kept in a small region called the nucleus. Another event is the first nonstop flight from London to Paris. -
Niels Bohr
Niels Bohr changed Rutherfords model and discovered that atoms have different energy levels. He said that the fixed energy level is like the rungs on a ladder. Another event that happened was the National Women's party was formed. -
Erwin Schrodinger
Erwin Schrodinger discovered that electrons move in orbitals. The answers to his equations were called the quantum mechanical model. The quantum mechanical model restricts energy of electrons to a set value. Another event that happened was 3 men danced the charleston for 22 hours. -
James Chadwick
James Chadwick confirmed that there are both protons and neutrons in the nucleus. By using cathode-ray tubes he found rays that were traveling in opposite directions. Another event that happened was "Mickey Mouse" and "Silly Symphony" comics were syndicated.
