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What are isotopes
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Atoms with the same number of protons (for example,
carbon with six) but a __different__ number of __neutrons___ |
What is an ion
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When an atom loses_ or _gains_one or more electrons,
it becomes positively or negatively charged |
What is a covalent bond?
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Holds together two atoms that _share_
one or more pairs of electrons |
What is a nonpolar covalent bond
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Atoms that share electrons equally
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What is a polar covalent bond
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Because atoms share the
electrons_unequally_, there is slight difference in charge between the two poles of the bond; water is an example |
What happens in a hydrogen covalent bond?
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An atom or a molecule interacts
weakly with a hydrogen atom already taking part in a polar covalent bond. |
Polar substances are
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Hydrophilic(water-loving)
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Nonpolar substances are
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hydrophobic (water-dreading)
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The interior of living cells is near pH =
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7
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What are bases?
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Substances that release ions such as
OH— (hydroxide ions) that can combine with hydrogen ions |
What is a buffer system?
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Is a partnership between a weak acid
and the base that forms when it dissolves in water |
Buffer molecules combine with, or release what?
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H+ to prevent drastic changes in _pH__
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