UNIT 3:
BONDING
WHAT IS BONDING???
1.Combination of atoms to form a compound (with
different properties)
2. Determined by electrons in atoms
3. Why bond?
 To increase stability
 To decrease energy
 To fill valence!!
4. A balanced combination of positive and negative
ions.
5. Simplest whole number ratio
OCTET RULE
Chemical compounds form so that each
element has a full octet of electrons in its
highest energy level.
 This can happen through gaining, losing, or
sharing electrons.

AGENDA 11/17/14

Review Unit 5 Tests
 Redo
policy
 Before Thanksgiving Break?

Review Ionic Compounds
 Properties

Continue Puzzle Piece activity
 Let’s

Clarify the directions
HW: Finish analysis questions for Activity
TYPES OF BONDING

Ionic Bond
 The
chemical bond resulting from electrostatic
attraction between positive and negative ions.
 Metals tend to lose electrons and form cations.
 Nonmetals tend to gain electrons and form anions
IONIC COMPOUND PROPERTIES
 Solid
state is a crystalline structure
 Hard, brittle solids
 High melting point
 NaCl
 Do
is 801oC
not conduct electricity as solids
 Do conduct as liquids and solutions
 Not discreet molecules, instead called formula
units
Puzzle Method
Identify charges of both the cation and the
anion.
 Collect puzzle pieces that correspond to the
ions.
 Adding more of only those charges, continue
adding pieces until you have a complete and
stable compound.

EXAMPLES….
Sodium Oxide
 Calcium Sulfide
 Aluminum Chloride

LET’S CLARIFY
Each pair needs new puzzle pieces
 The goal of fitting the pieces together is to
make a complete rectangle or square.
 Cations can only bond with anions!!


Your job is to make 20 combinations
 Do
Not try the Naming Yet!!!
AGENDA 11/18/14

Finish Formula Writing Lab
 Homework
for tomorrow
Go Over Unit 5 Test
 Collect Formula Writing Lab (3 and 8)

1

per group
Notes on writing and naming Ionic Compounds
INTRO TO FORMULA WRITING LAB

Meet with your lab partners

Compare answers to analysis questions , and your
conclusions.

Determine which of the two labs you will turn in.

Both partners names should be on the lab.
WHITE BOARDS ARE BACK!!

Get into your white board groups

One marker per group
PRACTICE FORMULA WRITING

Write the correct formula for the following
cation and anion pairs:
1.
2.
3.
4.
5.
Na+ and ClMg+2 and FC-4 and H+
Ag+3 and O-2
Ag+3 and N-3
Bonus Question: Is there a pattern you notice
between the charges on the ions and the
subscripts in the formulas?
CRISS-CROSS METHOD
Identify charges of both the cation and the
anion.
 Switch the charge value to be the opposite
ion’s newest subscript.
 Repeat for the other ion.
Example:

Ag+3
Ag2O3
O-2
ONE EXCEPTION

Ag+3 and N-3

Do the criss-cross method

If the subscripts can be reduced…reduce them!
NAMING AN IONIC COMPOUND…



Cation is always named first
Cation  take the name of the element
 Transition metals  use the formula to find the
charge (Roman numeral = charge)
Anion
 Monatomic (only one element) end in –ide
EXAMPLES…




CaF2
 calcium fluoride
Li2S
 Lithium sulfide
FeCl2 (This is a transition metal)
 Iron (II) chloride (ferrous chloride)
FeCl3 (This is a transition metal)
 Iron (III) chloride (ferric chloride)
MORE EXAMPLES…

PtO2
 Platinum

CuBr
 Copper

(I) bromide (cuprous bromide)
Zn3N2
 Zinc

(IV) oxide
(II) nitride (Zn is almost always +2)
Sn3P2
 Tin
(II) phosphide (stannous phosphide)
MORE PRACTICE…




Ca(OH)2
 Calcium hydroxide
NaSCN
 Sodium thiocyanate
Al2(CrO4)3
 Aluminum chromate
Mg(NO2)2
 Magnesium nitrite
PRACTICE, PRACTICE, PRACTICE…

NH4Cl
 Ammonium

Au2(CO3)3
 Gold

(III) carbonate
Pb(CN)4
 Lead

chloride
(IV) cyanide
FePO4
 Iron
(III) phosphate
AGENDA 11/18/14
Review Ionic Formula Writing
 Notes on Polyatomic Ions

 Naming

Notes on naming Covalent Compounds
 Properties

of covalent compounds
HW: Naming monatomic and polyatomic
formulas
COVALENT MOLECULES

Bonds that exist between two non-metals
 Two

anions!!
Both atoms want to gain electrons so they
share electrons in bonds to complete their
octet.
MOLECULAR SUBSTANCES

These exist between two different anions.
 Ex:
Carbon monoxide, CO, C==O
Many different solid forms, not crystalline
 Relatively low melting and boiling point.
 Poor conductors in all states!
 Do not dissolve in water very well.


Organic compounds are examples of molecular
substances.
NETWORK SOLIDS

Bonds between one non-metal element
 Ex:
C60 Buckminsterfullerene Buckyballs
 Diamond, Graphite, and Carbon nanotubes
NETWORK SOLIDS
Different shapes in the solid form.
 High melting and boiling points
 Often hard and brittle
 Non-conducting solids
 Do not dissolve in water well

NAMING COVALENT COMPOUNDS
First element using full element name
2. Second element name as if it were an anion
(-ide)
3. Use prefixes to denote # of atoms present for
both of the elements
- exception: mono is NOT used for the first
element.
Ex: CO  Carbon monoxide
Mono, di, tri, tetra, penta, hexa, hepta, octa,
nona, deca
1.
PREFIXES
One  mono Two  di Three  tri Four  tetra Five  penta Six  hexa Seven  hepta Eight  octa Nine  nona Ten  deca
EXAMPLES:





N2O3
 dinitrogen trioxide
N2O5
 Dinitrogen pentoxide
Xenon tetrafluoride
 XeF4
Oxygen dichloride
 OCl2
Diphosphorus trioxide
 P2O3
AGENDA 11/20/14
Review all types of naming
 Notes on metallic substances
 Practice Practice Practice


HW: Naming covalent compounds
NAME ALL OF THESE CORRECTLY!!
1. S2F3
4. PbO2
2. BeS
5. LiOH
3. CO2
6. NCl3
METALLIC BONDS: WHEN METALS COME
TOGETHER
METALLIC BONDING





Metallic bonds are described as a cluster of positive
metal ions surrounded by a sea of their shared valence
electrons.
Metallic Bonding is the type of bonding found in metallic
substances.
The positive ions remain fixed in a crystal lattice, while
the loosely-held valence electrons move freely
throughout the entire crystal.
Melting/boiling points between covalent and ionic
compounds.
Not soluble in water.
A Model of Metallic Bonding
The positive metal ions
are surrounded by a huge
cloud of free flowing electrons.
Insert figure 8.9
PROPERTIES OF METALS EXPLAINED BY THE ESEA…



Metals are great conductors of electricity. Why?
Electricity can be described as a movement of charged
particles, so if you have mobile charged particles
present then electricity can flow.
For metals, the sea of electrons is basically a cloud of
mobile charged particles.
METALS ARE MALLEABLE AND DUCTILE
Malleable: Can be beaten into a thin sheet
 Ductile: Can be pulled into a wire.
 Why?
 If you add stress you force like charges closer
together. They repel each other and move
apart, but instead of shattering, the particles
rearrange with the sea of electrons.

HITTING A METAL
LAST PROPERTY: METALS ARE SHINY!





Metals are shiny!!
Why?
The valence electrons move within the “sea” around
the positive ions of the metals.
When the light wave hits the electrons in the “sea”, the
light “bounces” off of them or is reflected back by the
electrons.
When this light hits our eyes, the appearance we see
is that the metal is shiny.
SHINY METALS: