ATOM

1. Patrick and Alex ATOM

2. What is Atomism? • Atomism is a philosophy that states that the entire universe and everything in the history of existence is made up of tiny, indestructible, and indivisible particles. • Basically they are like the Lego'sof all matter. • Because the atom is such a topic of discussion, there are numerous theories on it.

3. Greek Atomism/Earth, Wind, Fire Model • The first known proposers of the theory of the atom even existing were the Greeks. • The Greeks thought that if you kept splitting matter then eventually you would get indivisible matter. Sadly though, they did not have the technology or necessary equipment to conduct any experiments, and thus could not prove anything.

4. Solid Sphere • The solid sphere model was developed by John Dalton around 1802. • He proposed that elements combined in to whole number ratios. • Dalton didn’t exactly know if the atoms could be put together but thought that atoms within the same element were also the same or identical.

5. Plum Pudding • Was the first model to give a general idea of what the atom supposedly looks like. • The model included electrons spread throughout the atom. • In this model the positive electrons are supposed to balance out the negative ones (negative charge = plum, positive=pudding). • Revealed that atoms have different parts to them and not just a solid sphere. • Created By J.J. Thomson in 1904 and was later disproved by Ernest Rutherford’s Gold Foil experiment.

6. Nuclear/Gold Foil • 1909 • In this experiment Rutherford set up a piece of gold foil. He then took a cathode ray and shot it at the foil. He was expecting all the particles to go through and most of them actually did. However some bounced back. • If all of the particles went through then that would mean that inside the atoms were nothing but empty space. • Not all of them went through so Rutherford theorized that there was something there. He called it the nucleus.

7. Atomic Model after the 3 previous models…