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So,
if one atom has a much greater
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affinity
for electrons than another, the
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two
may form an ionic bond. If two
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atoms
have equal electron affinities
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they
form covalent bonds. What if
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two
atoms are slightly unequal? In a
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molecule
of water for example,
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oxygen
has a greater affinity for
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electrons
than hydrogen, but not
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enough
to pull the electrons away
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completely
and form ionic
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bonds.
This is possible because there
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are
2 types of covalent bonds. Non-
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polar
covalent bonds are formed
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when
atoms share electrons equally,
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such
as in the examples above. But
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when
one atom has a greater affinity
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for
electrons in a molecule, the shared
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electrons
will spend more time around
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that
atom and the bond formed will be
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a polar
covalent bond.
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