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18 Cards in this Set
- Front
- Back
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a substance that cannot be broken down by chemical processes into simpler substances
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element
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elements are listed on
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the periodic table
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4 human elements that make up 96% of the human body
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nitrogen, oxygen, carbon, hydrogen
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usually elements exist in combinations called
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compounds
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properties of a compound are _________ different than those of an element
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different
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2 or more elements chemically combined in definite proportions
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compound
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nucleus is the
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center of an atom
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postivly charged
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protons
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0 charge
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neutrons
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negative charge
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electrons
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atom of the same element have contain the same number of electrons and therefore have______ net charge
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no
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1st level
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2 electrons
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2nd
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8 electrons
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3rd level
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18 electrons
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an atom that has gained or lost electrons
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ion
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atoms that lose electrons become
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postive ions
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atoms that gain electrons become
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negative ions
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atoms of the same element that have different numbers of NEUTRONS!
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isotopes
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