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Dalton
- Elements are made of tiny particles called atoms.
- Atoms can't be created or destroyed
- All atoms of a certain element are identical.
- Atoms of a different elements have different atomic weights.
- Chemical compounds are formed with atoms of other elements. He thought only one atom of each element could combine and he was proven wrong.
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Thompson
He showed that it was relatively easy to extract negatively charged particles from atoms.
This negatively charged particles are known as electrons, the experiment consisted of looking at the conduction of electricity through a gas at a low pressure.
it was found that there was a discharge from the cathode that caused the gas tube to fluoresce.
This discharge became know as cathode rays.
In the experiment, Thomson extracted electrons. https://www.youtube.com/watch?v=dehxVQAUqBs -
Rutherford
He had two hypothesis
Negative charge was distributed throughout the atom.
All positive charge was in the center.
He discovered that atoms have negative electrons orbiting around. https://www.youtube.com/watch?v=LMXNESnTc2c -
Bohr
He discovered that atoms have electrons that are orbiting around the nucleus.
Electrons continually commit radiation, they lose energy so the radius is always shrinking (This was wrong and he wanted to prove it)
He thought that if electrons really lose energy they would be sucked by the nucleus. In the contrary, if an electron is excited, it gets a higher energy level. https://www.youtube.com/watch?v=fm2C0ovz-3M -
Shrödinger
He formed a model of an atom as interacting waves; the vibrations were like a violin, they just were circular waves. https://www.youtube.com/watch?v=IOYyCHGWJq4 -
Heisenberg
He said that you can't know by measurement the specific position of a particle simultaneously. https://www.youtube.com/watch?v=TQKELOE9eY4