# Structural Formula

```Practice Drawing Lewis Dot Structures
at the top margin of page 4
H
Na
Cl
What
does the
number of dots
around the
atomic symbol
represent??
 The number of
valence electrons
The Rule
of 8
Atoms tend to gain, lose, or
share electrons until they
have eight valence
electrons.

Covalent bonds are
formed between nonmetals and non-metals

Lewis Dot Structure
H
Chlorine and
Hydrogen will
share their
electrons
Cl
H Cl
Note: Hydrogen
is content with 2
electrons, not 8.
Structural Formula
H-Cl
Bonding Pair- pairs of shared electrons within the
molecule
 Lone Pair- a pair of electrons in the valence shell of
an atom that does not participate in bonding
 Single bonds occur when a single pair of electrons are
Ex: NH3
shared between atoms

AmmoniaLewis Dot Structure
H
H
N
H
Structural Formula
H
H
H N HH N H
Hydrogen Gas
H2
H H
H H H-H
Chlorine Gas
Cl2
Cl Cl
Cl Cl
Cl-Cl
Ex: O2
Oxygen gas
O
O
Bonds
occur when
atoms share two
pairs of electrons
O
O
 Double
O=O
Ex: N2
Nitrogen gas
N
 Triple
N
Bonds form when
atoms share three pairs of
electrons
N N
N N
Carbon dioxide
O
C
O
O=C=O
Water
H-O-H
ACC: Dimethyl ether Structural Formula
Bellwork: Monday 3/26/2012
Count the atoms of each element in the following:
 Na2SO4
 (2) Sodium, (1) Sulfur, (4) Oxygen

2Al2(CO3)2
 (4) Aluminum, (4) Carbon, (12) Oxygen

Draw the Lewis Dot Structure and Structural
Formula for Chlorine gas (Cl2)
Monday 3/26/2012
Presentation Order P1














Allison
Juliet
Joey
Nicole
Kassandra
Andrew
Jristin
Austin
Tim
Fred
Michael
Sierra
Natalie
Lyndsie













If you don’t have your 3D
Joseph
model, you don’t present!
Destiny
Presentation and model
Brianna
will be LATE!
Caity
Sam
Presentation:
• Element Name / Molecule
Donovan
Name
Jordan
• Atomic Symbol / Molecular
formula
Katrina
• Atomic Number / Total
Cassidy
Molecular weight
Brenden
• 2 Interesting Facts
Quinn
•
Origin of name? Uses? Cool
things or facts? Etc.
Cecelia
•
NOT malleable, luster,
number of orbitals, etc.
Presentation Order P2














Angelo
Gary
Sabrina
Ronnie
Bryan H.
Leslie
Megan
Michael Vizzi
Brian C.
Angie
Bianca
Ty
Scarlett
Logan














If you don’t have your 3D
Robbie
model, you don’t present!
Richard
Presentation and model
Marukh
will be LATE!
Chris
Rachael
Presentation:
Kyle
• Element Name / Molecule
Sean
Name
Vanessa
• Atomic Symbol / Molecular
formula
Austin
• Atomic Number / Total
Wesley
Molecular weight
Trey
• 2 Interesting Facts
Savanna
•
Origin of name? Uses? Cool
things or facts? Etc.
Jordan
•
NOT malleable, luster,
number of orbitals, etc.
Mike Verrochi
Presentation Order P3















Mary Ann
Isaiah
Andrew
Kolton
Dylan M.
Brooke
Priscilla
Kristina
Brooklyn
Allison
Austin
McKenzie
Fermin
Joey
















Michael R. If you don’t have your 3D
Dawson
model, you don’t present!
Angelica
Presentation and model
Jasmine
will be LATE!
Jordan H.
Sam
Dylan P. Presentation:
• Element Name / Molecule
Michael C.
Name
Joseph
• Atomic Symbol / Molecular
formula
Lindy
• Atomic Number / Total
Molecular weight
Tiffany
• 2 Interesting Facts
Isabel
•
Origin of name? Uses? Cool
things or facts? Etc.
Jordan W.
•
NOT malleable, luster,
Jon Jon
number of orbitals, etc.
Charlie
Presentation Order P5


















Ean
Elizabeth
Michael
Derek
Riley
Matt
Josh
Taylor
Brody
Gloria
Alyssa
Steven
Maxine
Kellie
Liya
John
Rachel


















Hayden
Trev
Mason
Andrew
Nikki
Brian
Carolina
Vanessa
Kahlil
Issac
Edrian
Sierra
Allie
Wendy
Justin
Cerys
Gracyn
Cameron
If you don’t have your 3D
model, you don’t present!
Presentation and model
will be LATE!
Presentation:
•
•
•
•
Element Name / Molecule
Name
Atomic Symbol / Molecular
formula
Atomic Number / Total
Molecular weight
2 Interesting Facts
•
•
Origin of name? Uses? Cool
things or facts? Etc.
NOT malleable, luster,
number of orbitals, etc.
Presentation Order P6













Abby
Riley H.
Sarah
Paloma
Francis
Edward
Graham
Celia
Dani
Cassidy
Mackenzie
Carlson
Jake













If you don’t have your 3D
Linh
model, you don’t present!
Aspen
Presentation and model
Steven
will be LATE!
Riley C.
Alex
Presentation:
Kylee
• Element Name / Molecule
Name
Christina
• Atomic Symbol / Molecular
Paige
formula
• Atomic Number / Total
Alissa
Molecular weight
Nate
• 2 Interesting Facts
•
Origin of name? Uses? Cool
Haley
things or facts? Etc.
Nidia
•
NOT malleable, luster,
number of orbitals, etc.
James
Practice Drawing Covalent Bonds

Using the transparent
cards on the table, show
how the electrons can
be shared in the
following covalent
bonds:
 I2
 Cl2
 CO2
 H2O
 O2
 N2

Remember: the electrons
MUST be between the
symbols. You also can
only have 2 on each
side…So you may need to
turn and twist the
pictures until it looks the
way it should!
NO Bell Work: Tuesday 3/27/2012
 Interims
today! All you need is a pencil and
a scantron. Good luck! When you are done,
book, or work on homework for other classes.
 Don’t
forget! Your tissue box is DUE
THURSDAY!!
 Period
2 – Once you finish, if you have not
presented, come up to me so you can present
Bellwork: Wednesday 3/28/2012
H
H H C H
H C H H
F
H F
F NF
F N F
Draw the Lewis Structure and
Structural Formula for:
1.
CH4
2.
NF3
3.
HI
I H
I H
What is in a name?
A
chemical formula tells what
elements are in a compound,
and the exact number of
atoms of each element
needed.
 Ex: NH3, H2O
 Covalent
bonds and Ionic
bonds are named in different
ways, but both show the
elements and numbers of
atoms in their own ways
Name
this
compound:
Ba(Na)2
Banana!

The first atom listed…
 Is capitalized
Ex: CO2
 Is written as the name of that element
 Includes a prefix if there are more than one of that atom

The second element…
 Is written in lowercase
 May include a prefix to tell how many atoms there are
 Is shortened
 Ends in the suffix “-ide”
…is Carbon dioxide

When shortening a name:
Eliminate the second syllable at the first vowel
 Exchange this for the suffix “-ide”

chlorine
sulfur
nitrogen
fluorine
chloride
sulfide
nitride
fluoride
Br
bromine
bromide
O
oxygen
oxide
H
hydrogen
hydride
I
iodine
iodide
Number
1- 1st
1-
2nd
Prefix
None used
mono- (use
only for Oxygen)
Example
n/a
Name
n/a
O
monoxide
2
di-
O2
dioxide
3
tri-
H3
trihydride
4
tetra-
Cl4
tetrachloride
5
penta-
O5
pentoxide
6
hexa-
Cl6
hexachloride
7
hepta-
S7
heptasulfide
8
octa-
Br8
octabromide
9
nona-
H9
nonahydride
10
deca-
C10
decacarbide
P2O5
Diphosphorous
•Is capitalized
•Is written as the name of that
element
•Includes a prefix if there are more
than one of that atom
pentoxide
•Written in lowercase
•With a prefix to tell how
many atoms there are
•Shortened, and ends in
the suffix “-ide”
Naming Diatomic Covalent Molecules
Even though the following gases travel in pairs
(diatomic)…their names are simple…
O2
 Oxygen gas
 F2
 Fluorine gas
 I2
 Br2
 Bromine gas


 Iodine gas

N2
 Nitrogen gas
Cl2
 Chlorine gas
Naming Covalent Bonds Practice Problems:
 CO
 XeF3
 Carbon monoxide
 CO2
 Carbon dioxide
 PBr3
 Phosphorous
tribromide
 CCl4
 Carbon tetrachloride
 Xenon trifluoride
 AsI3
 Arsenic triodide
 IF5
 Iodine pentafluoride
 N2S5
 Dinitrogen
pentasulfide
Example #1-Names to Formulas
Sulfur trioxide
1. Write symbols of elements
2. Write number of atoms
S1O3
If no prefix, then 1 is implied
Final
and
notFormula
written
Example #2-Names to Formulas
Dichlorine heptaoxide
1. Write symbols of elements
2. Write number of atoms
Cl2O7
Final Formula
Example #3-Names to Formulas
Oxygen difluoride
1. Write symbols of elements
2. Write number of atoms
O1 F2
If no prefix, then 1 is
impliedFinal
and not
written
Formula
Example #4-Names to Formulas
Dinitrogen tetraoxide
1. Write symbols of elements
2. Write number of atoms
N2O4
Final Formula
Example #5-Names to Formulas
Phosphorus pentachloride
1. Write symbols of elements
2. Write number of atoms
P1Cl 5
If no prefix, then 1 is implied
Final
and
notFormula
written
Example #6-Names to Formulas
Dinitrogen monoxide
1. Write symbols of elements
2. Write number of atoms
N2O 1
If no prefix, then 1 is implied
Final
and
notFormula
written
Example #7-Names to Formulas
Carbon monoxide
1. Write symbols of elements
2. Write number of atoms
C1 O 1
If no prefix, then 1 is implied
Final
and
notFormula
written
Example #8-Names to Formulas
Sulfur hexafluoride
1. Write symbols of elements
2. Write number of atoms
S1 F6
If no prefix, then 1 is implied
Final
and
notFormula
written
```