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Democritus' atom
Democritus, a Greek philosopher who thought and or announced his idea that matter is made of tiny, indivisible unbreakable particles that he had called atomos, which means atom. his idea was rejected because he did not have the proper equipment to conduct his experiment. https://youtu.be/UDIprICe9kg This video shows all of the scientist and their models in this time line. -
John Dalton's atom
John Dalton who was a English chemist, he had an idea for a theory about atoms. His theory was called Dalton's Atomic theory. He learned that elements are made of atoms. All atoms that are the same element are alike.Compounds are made of molecules was another discovery of his. that atoms of different elements differ from each other. https://youtu.be/UDIprICe9kg This video shows all of the scientists models. -
Lord Ernest Rutherford
Ernest Rutherford did a famous experiment called the gold foil experiment. He used a thin gold foil sheet, he used a special piece of equipment to shoot alpha particles or positiviely charged particles at the gold foil. Most particles had gone through the sheet of foil but some particles went back or were deflected. And atoms are made of small positive nucleus; positive nucleus repels and positive alpha particles. https://youtu.be/UDIprICe9kg This shows all of the models in this timeline. -
J. J. Thompson's atom
J. J. Thompson was a scientist who discovered electrons when he was doing or conducting a experiment with gas discharge tubes. He saw that there was movement in the tube and called it movement cathode rays. they moved from one negative part of the tube to a positive part of the tube. Seeing the negatively charged particles were electrons. https://youtu.be/UDIprICe9kg This video shows all of the models from all five scientists. -
Niel Bohr's atom
Niel Bohr, a physicist who made an model of an atom that looked very similar to the solar system. The model showed the electron looking like it was orbiting the nucleus like planets orbiting the sun. He found out that each level can hold a certain amount of electrons. So when there are more electrons there are more energy levels. https://youtu.be/UDIprICe9kg This shows all of the models.
