Writer: Timothy Fiore
 Chemical Formula: Covalent and Ionic- Page 3
 Bonding Diagrams: Covalent and Ionic- Page 8
 Naming Compounds (Dear Timothy)- Page 12
 VSEPR Theory- Page 15
 Polarity- Page 18
 Intermolecular Forces- Page 20
 Comics- Page 22
1.
2.
3.
4.
5.
Determine the charge on each element/ or
polyatomic ion
Write the charge above the element or polyatomic
ion
Criss-cross the two numbers and write them as
subscripts
Use parentheses around polyatomic ions if there is
more than one
Simplify so that the formula has smallest wholenumber ratio
Page 3
 Al O
 Al3 O-2
 Al2O3
 Ca SO3
 Ca2 SO32
 Ca2 (SO3)2
 Ca SO3
Page 4
 To write the formula for a covalent bond, use the Greek
prefixes in the name of the compound. The prefix is
what determines the subscript. If there is only one
atom in the first element, omit mono.
Mono
1
Hexa
6
Di
2
Hepta
7
Tri
3
Octa
8
Tetra
4
Nona
9
Penta
5
Deca
10
Page 5
 Sulfur Dioxide
1S
 SO2

2O
 Dibromine Heptaoxide
2Br
 Br2O7

7O
Page 6
Dear editor,
Throughout all the articles I have read, this last
one was the easiest to understand. Writing chemical
formulas, specifically for covalent compounds, made a
lot of sense to me. This is because all I really had to do
was memorize the Greek prefixes in order to write the
formulas. I really appreciate the way you explained how
to write the formulas. You were a great help. I look
forward to reading more of your magazines and articles.
Sincerely, Matt
Page 7
 Bonding diagrams predict the compound formed between
a metal and non-metal
 To make a bonding diagram one must know the electron
dot diagram
 Element with the smaller number of electron goes to the
one with more
http://hyperphysics.phy-astr.gsu.edu/hbase/pertab/perlewis.html
Page 8
Page 9
 Use covalent bonding diagrams made with Hydrogen




and elements from groups 14, 15, 16, and 17
Called the Lewis Dot Formula
Must get each element to have 8 electrons except
Hydrogen (2)
Do not have to use electron dot structures
Put element that makes most bonds in middle (Like
elements from group 14)
Page 10
http://www.docbrown.info/page04/4_72bon
d3.htm
Page 11
Dear Timothy,
I am in chemistry now and I am having trouble naming compounds. Can you
teach me how to do that?
Sincerely, Spencer
Dear Spencer,
Yes! I can definitely help you name compounds. The compounds you will be
using are called binary compounds. This means the compound is composed of 2 elements.
First you have to know what type of compound it is. If the compound is made up of a metal
and a non-metal that means it is ionic. This means the metal in the formula lost an electron
to form a positively charged ion (cation). The non-metal in the compound has a negative
charge called anions. Ionic compounds also sometimes include a polyatomic ion and a
metal. Naming a regular ionic compound (metal and non-metal) is very easy. All you have
to do is write the name of the first element, and the second element's stem with “ide” added
to it. If a polyatomic ion is paired with a metal, it is still very easy. You just write the name
of the element first, and the polyatomic ion second. No changes are necessary. If you are
dealing with transition metals (from groups 3-12) you must first determine the charge on
the metal. After that is done you write the charge as a roman numeral after the metal. I
know that might seem like a lot to think about just to name an ionic compound, but I
promise after you see the examples on the next page it will be a lot easier.
Page 12
Naming Ionic Compounds:
NaCl------Sodium Chloride
Al(PO3)------Aluminum Phosphite
NiBr2------Nickel(II) Bromide
Dear Spencer,
As you can see, naming an ionic compound is not tough. If you are dealing with
a two non-metals then the compound becomes covalent. The elements in covalent
compounds are Hydrogen, and all the elements in groups 13-16. To name covalent
compounds you must first know the greek prefixes. You can find a table with the prefixes on
page 5. In the formula to find out what prefix to use you look at the subscripts of each
formula. Once you know the prefixes you just write out the first element name with the
prefix attached, then the second element stem name with the prefix attached and “ide’’
added to the end of it. It is pretty much the same as naming an ionic compound but greek
prefixes are attached to the words. Remember mono is omitted if you are dealing with the
first element in the compound
Page 13
Naming Covalent Compounds:
P2I5------Diphosphorous pentaoxide
CS2------Carbon disulphide
Cl2O7------Dichlorine heptaoxide
Dear Spencer,
I hope that what I have shown you helped you name
compounds. There is also a metallic compound formed
between metals but you won’t ever have to name those so
don’t worry.I assure you, they are not too hard once you
practice!
Sincerely, Timothy
Page 14
Valence Shell Electron Pair Repulsion theory (VSEPR)
predicts the shape of a molecule or a covalent
compound. It is a lot similar to the bonding diagram for
covalent compounds, but it uses geometry shapes
instead of straight lines. The shared and unshared pairs
of electrons repel from each other, or try to get as far
away as possible. This is what makes the shape of the
molecule or compound. There are 6 main shapes in the
VSEPR theory.
Page 15
Linear: There can be 2 or 3 elements and when they bond there is zero
unshared pairs of electrons.
Bent: There are three elements. The central atom can have 1 or 2 unshared
pairs of electrons.
Trigonal Planar: There are four elements. Three of the elements bond to
the central element and as a result there is zero unshared pairs of
electrons.
Pyramid: There are four elements. Three elements are bonded to central
element and as a result there is 1 unshared pair of electrons.
Tetrahedral: There are five elements in this shape. The four outer
elements bond to central element and there is zero unshared pairs of
electrons.
Trigional Pyramid: There are six elements in this shape. This shape is
made from elements in period 3.
Page 16
http://www.public.asu.edu/~jpbirk/CHM113_BLB/Chpt09/sld011.htm
Page 17
Polar bonds are bonds where electrons are shared
unequally between atoms. In the bond, the element
with the most electronegativity will pull the electrons
closest to itself. On the periodic table, electronegativity
increases as it goes to the right and decreases as it goes
down. Each atom has a different pull on electrons. The
bond is not polar if electrons are shared equally between
the two atoms. If the elements are the same then they
have the same pull on the shared electrons. Generally, a
molecule will always be polar if the elements outside are
different. Oppositely, same atoms around a central atom
will be non polar.
Page 18
http://www.800mainstreet.com/5/0005009-polar-molecules.htm
Page 19
Hydrogen Bond: A hydrogen bond is formed between Hydrogen and a
lone pair electron found in Flourine, Oxygen, or Nitrogen.
Dipole-Dipole Force: This force is formed between molecules that are
polar and covalent. This is because of the electronegativity between nonmetals.
London Dispersion Forces: Also known as Van der Waals Force. This
force is made between covalent molecules that are not polar. Comes from
the fact that electrons are always moving. Dipoles occur because of
uneven electron distributions.
Ionic Solids: These are ionic compounds (metal and non-metal). They
are formed do to electrostatic attraction. Ionic bonding is higher as atoms
get smaller, and higher as charges get bigger
Page 20
http://preparatorychemistry.com/bishop_at
traction_strengths.htm
Page 21
http://faaizajaz.wordpress.com/2010/10/05/chemistry-jokes-are-funny/
http://www.chem.uci.edu/~potma/cartoons.htm
Page 22