Transcript Lewis structures & molecule shapes

Lewis structures & molecule
shapes
AB or AB2 – linear
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If there are only two atoms the shape will be
linear – there are no
unshared electrons
around the central atom
H2 is a great example of linear, as is HCl
 CO2 is also linear
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AB3 – Trigonal Planar
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There are three atoms and the central atom does
not have any unshared pairs of electrons
BF3 is an example, so is CH2O
The Lewis Structure will have 3 pairs around the
central atom being shared with other atoms, and
no other electrons around the central atom!
AB4 - Tetrahedral
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There are four atoms bonded to the central atom
with no unshared pairs of electrons on the central
atom.
CH4 is an example
The Lewis Structure will have 4 pairs of electrons
shared between the central atom and other atoms,
with no other electrons around the central atom!
AB3E – Trigonal Pyramidal
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Three atoms are bonded to the central atom, and
the central atom has one pair of unshared
electrons.
NH3 is an example
The Lewis Structure will have one unshared pair
of electrons around the central atom as well at the
other three pairs bonded to the three atoms
AB2E or AB2E2 –
Bent or Angular
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The central atom has two atoms bonded and two
pair of unshared electrons
H2O is an example
The Lewis Structure will have two unshared pair
of electrons around the central atom and two
other pairs of electrons bonded to other atoms
Practice
Draw the Lewis Structure (or electron dot
diagram) and then determine the shape for
the following molecules
 AlF3
 SiO2
 SF2
 PCl3
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Practice
Draw the Lewis Structure (or electron dot
diagram) and then determine the shape for
the following molecules
 AlF3
AB3
Triagonal Planar
 SiO2
AB2
Linear
 SF2
AB2E2
Bent or Angular
 PCl3
AB3 E
Triagonal Pyramidal
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Practice
Draw the Lewis Structure (or electron dot
diagram) and then determine the shape for
the following molecules
 CHF3
 CO2
 COF2
 GaBr3
 Na2S
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Practice
Draw the Lewis Structure (or electron dot
diagram) and then determine the shape for
the following molecules
 CHF3
AB4
Tetrahedral
 CO2
AB2
Linear
 COF2
AB3
Triagonal Planar
 GaBr3
AB3
Triagonal Planar
 Na2S
AB2E2
Bent
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Practice
Draw the Lewis Structure (or electron dot
diagram) and then determine the shape for
the following molecules
 NF3
 CO3-2
 CF4
 POH
 C2H2
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Practice
Draw the Lewis Structure (or electron dot
diagram) and then determine the shape for
the following molecules
 NF3
AB3E
Trigonal Pyramidal
 CO3-2
AB3
Triagonal Planar
 CF4
AB4
Tetrahedral
 POH
AB2E
Bent
 C2H2
AB2
Linear (both carbons)
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