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500 BCE
Democritus
He believed in "Atomos". This means that everything is split up into half and eventually it has to end with an atom. -
500 BCE
Heraclitus
He believed that everything was made of fire. -
350 BCE
Aristotle
He believed that everything was made from four elements. Earth, Fire, Earth, and water. -
Dalton's Atomic Theory
- All matter is composed of small particles
- All atoms of elements are identical in sizes
- Atoms cant be subdivided
- Atoms have to have whole number ratios
- Chemical reactions change the bonds
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Cathode Ray
A cathode ray adds voltages through two separate tubes and whenever they interact it lights up. -
Why it was important?
When he put in two positive charges the light till went off. They should have repelled each other, but the light still went off. This is showing that there was a negative charge involved. Thus, an atom does have more parts then we believed. -
What is the plum pudding model
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Ernest Rutherford
He discovered the nucleus. -
Bohr Model
He found out that electrons bounce down and back from the center of the nucleus. When it touches down, the different colored light emits off of it. -
Line Emission Spectrum
They put in an electron and the light changes based off of the frequency. The electron falls and rises to this frequency based on how much energy its given. -
Erwin Schrödinger
He said that electrons just are just near the atom in a thick dense outside. They do not revolve just sit there. -
Chadwick
Chadwick founded the neutron. He took the mass of a proton and saw that there was more mass to spare. He then figured there was a smaller atom that had neither positive nor negative charge.
