Bonding
POGIL #3- Lewis Structures
How are Lewis structures used to model molecules?
Name:
Information
1-
Drawing Lewis Structures
A systematic approach is usehl for drawing Lewis structures of more complex molecules:
1. Sum the valence electrons for
4
atoms in the molecule.
2.
Connect all atoms to the central atom using a single covalent bond. The central atom is
usually written first in the formula. Atoms are often in the same order
as
in the formula.
3. For each single covalent bond used, subtract two electrons fiom the total determined in
#l. Maximize the number of octets by distributing the remaining electrons
as
lone pairs.
4.
Place any leftover lone pairs on the central atom, even if the octet rule is violated.
Ex- Draw the Lewis structure for CH2C12.
0
CHzClr
ly
=
20
\/~Icwc
e-
5;
It
bCd5
*nd
6
bc
fi
H
0
U
0
I
0
26--8=IL
lfc[
-c-cG
1
.,
CI
-
C-GI
-
I'
I
.'
I
II
12
T~lr\hhifl
eleckms
,-
d;.;~]
awmj
6
The&
mc
n*
rea4;11)~
t8
ektkat\s
wdh
die
7
chldirrr
tb1
do
not
ele'fnpj
nd
411
4
&
4avc
5iog
IC
cova
ale-f
beqds
hrjc
afi
4cte4
4,
OCH~
Critical Analysis Questions
1. Determine the total number of valence electrons in phosphorus trichloride, PC13.
-
2.
Use the rules above to draw a Lewis structure for PC13
3. How many single covalent bonds are present? Lone pairs?
