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    | • | From quantum rules, electrons don’t like to
    be packed into a small 
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    |  | space, either in atoms or in ionized gas 
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    | • | At normal ionized gas densities, electrons are so spread out 
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    |  | quantum rules don’t matter. 
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    | • | As high enough ionized gas densities, quantum rules need to be 
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    |  | considered, just has they have been in atoms 
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    | • | Think of each “atom sized” region of space having a set of energy 
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    |  | levels associated with it  (although
    it is really more complicated) 
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