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15 Cards in this Set
- Front
- Back
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Atom |
the smallest particle into which and element can be divided and still be the same element |
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John Dalton 4 parts of the Atomic Theory |
Theory states that 1. all matter is made of atoms, 2. atoms cannot be created, divided, or destroyed, 3. All atoms of a certain element are identical, 4. atoms join with other atoms to make new substances |
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J.J. Thomson |
He Thought that an atom was a positive sphere with the electrons mixed |
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Electrons |
These negatively charged particles |
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Nucleus |
a small, dense center that has a positive charge and is surrounded by moving electrons |
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Protons |
Positively charged particles in the nucleus Their mass is about 1u |
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Aristotle |
A Greek philosopher that did not agree (did not believe in atoms) |
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Democritus |
Greek philosopher thought that you would end up with a particle you cannot cut (Atoms) |
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Ernest Rutherford |
found out that atoms have a nucleus then found that electrons move around the nucleus |
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Niels Bhor |
Bhor's theory was that the electrons moved around the nucleus in a circular pattern at a certain distance apart |
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Netrons |
uncharged particles |
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Electron cloud |
Theory says that electrons move within an area around the nucleus called the electron cloud |
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Atomic Number |
the number of protons in the nucleus of an atom |
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Isotopes |
are atoms of the same element that have different numbers of netrons |
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Mass Number |
the total number of protons and neutrons in an atoms nucleus |
