Chapter 2 - Atoms and Molecules
Atoms
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build molecules
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composed of subatomic particles
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protons
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neutrons
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electrons
- energy levels
- atomic number
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# protons = # electrons
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# neutrons varies
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atomic mass
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energy levels
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elements
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composed of a specific type of atom
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have a unique atomic number
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have unique characteristics
Molecules
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atoms held together by chemical bonds
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full outer energy level gives stability
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chemical bonds
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ionic bonds (attraction of ions)
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covalent bonds (atoms share electrons)
© Carol L. Wymer, 2003