1. Ionic and Metallic Bonding
Sodium chloride
Nitrogen dioxide
Chapter 7
Carbon monoxide
Hydrochloric acid
Calcium fluoride
Ionic and Metallic Bonding
Magnesium sulphate
Hydrogen peroxide

2. MOLECULAR VS. IONIC COMPOUNDS
MOLECULAR COMPOUNDS:
1. Low melting & boiling points
2. Solids, Liquids, and Gases at room temp.
3. Sharing of valence electrons
4. Two or more Nonmetallic elements
5. Contain covalent bonds
EX:
H2O CO2

3. MOLECULAR VS. IONIC COMPOUNDS
1. High melting & boiling points
2. Composed of ions (cation and anion)
3. Electrically neutral
4. Crystalline solids at room temperature
-coordination #, 3D patterns
5. Composed of a Metal and Nonmetal
6. Contains Electrostatic Bonds
EX:
NaCl MgCl2

5.                                             Ionic Bonds:
One big greedy thief dog!
Ionic bonding can be best imagined as one big greedy dog steeling the other dog's bone.  If the bone represents the electron that is up for grabs, then when the big dog gains an electron he becomes negatively charged and the little dog who lost the electron becomes positively charged.  The two ions (that's where the name ionic comes from) are attracted very strongly to each other as a result of the opposite charges.

6. CHEMICAL FORMULA: Shows the kinds and number of atoms in the
smallest representative unit
of the substance.

7. 2. Shows the lowest whole-number ratio
IONIC FORMULA:
1. Ionic compounds exist as formula units.
2. Shows the lowest whole-number ratio
of ions present in an ionic compound
(formula unit).
EX:
NaCl (sodium chloride) Na+1 Cl-1
1:1 ratio
MgCl2 (magnesium chloride) Mg+2 Cl-1
1:2 ratio

8. Ionic Compounds

9. How to Write an Ionic Formula:
1. Write down symbols
2. Determine Ionic Charges
3. Charges must cancel each other out
(equal zero)
if not, use criss-cross method to form subscripts to cancel out charges

10. EXAMPLES:
Potassium Bromide
K Br charges cancel KBr
Magnesium Oxide
Mg O-2 charges cancel MgO
Aluminum Nitride
Al N-3 charges cancel AlN
Magnesium Chloride
Mg Cl charges don’t cancel, criss-cross MgCl2
Sodium Sulfide
Na S charges don’t cancel, criss-cross Na2S
Aluminum Oxide
Al O charges don’t cancel, criss-cross Al2O3

11. Naming an Ionic Formula:
1. Write the name for the metal and nonmetal
2. Check to see if the metal has more than
one charge (Cu, Fe, transition metals)
3. If metal has more than one charge, you
must do a “reverse” criss-cross to
determine formula
A Roman Numeral goes between the two names
4. Change the nonmetal ending to IDE

12. KBr potassium bromide Na2O sodium oxide MgS magnesium sulfide
EXAMPLES:
KBr potassium bromide
Na2O sodium oxide
MgS magnesium sulfide
Cu Br copper II bromide
As O arsenic V oxide
Fe2 O3 iron III oxide

13. Metallic Bonds

14. Consist of the attraction of the free-floating valence electrons for the positively charged metal ions.
Lets Remember:
Good conductors of electricity & heat
Ductile & malleable
Metals have 1,2, or 3 valence electrons
Low ionization energies :
(easy to remove valence electrons)

15. 1. Valence electrons don’t belong to any individual atom.
Therefore:
1. Valence electrons don’t belong to any
individual atom.
2. Valence electrons exist as a sea around closely
packed metal cations.
Cation
Sea of valence
electrons

16. 3. Metal cations are insulated from one another
by a sea of drifting valence electrons
(ballbearings in oil)
4. Metals are simplest crystalline solids
5. Orderly compact pattern
Cation
Sea of valence
electrons

17. Metallic Bonds:  Mellow dogs with plenty of bones to go around
These bonds are best imagined as a room full of puppies who have plenty of bones to go around and are not possessive of any one particular bone.  This allows the electrons to move through the substance with little restriction.  The model is often described as the "kernels of atoms in a sea of electrons."

18. Laws of Proportions I. Law of Definite Proportions:
A chemical compound always contains the same elements in exactly the same proportions by mass.
Any two samples of a given compound are made of the same elements in exactly the same proportions by mass.

19. Law of Definite Proportions:
EX: H2O
2g 16g :8 mass ratio
always for any compound of water
CO and CO2

20. Laws of Proportions II. Law of Multiple Proportions:
(comparing 2 different cmpds)
When two elements combine to form two or more compounds, the mass of one element that combines with a given mass of the other is in the ration of small whole numbers.

21. Law of Multiple Proportions:
EX: Carbon reacts with oxygen to form
2 cmpds.
Cmpd. A contains 2.41 g of C for each
3.22 g of O. Cmpd. B contains 6.71 g of C for each 17.9 g of O. What is the lowest whole number ratio of C that combines with a given mass of oxygen?

22. Law of Multiple Proportions:
EX: Two compounds that contain H and O are hydrogen peroxide and water.
1. Demonstrate the Law of Definite Proportions for these two compounds.
2. Find the mass ratio of oxygen in these 2 cmpds.