1. Ionic Versus Covalent Compounds
Metal + Non-Metal atoms
“Give & Take” electrons
Covalent
Non-Metal atoms ONLY!
“Share” electrons
How to tell if a compound is ionic or covalent?
Ask......
Is there a metal?
Yes = Ionic
No = Covalent

2. Ionic Compounds
Ionic are made up of positive and negative ions organized in a pattern
Negative-positive attract.
Negative-negative and positive-positive repel.
Ionic compounds form solid crystals
Ionic compounds are like a solid stack of bricks.
A salt shaker contains thousands of small pieces of NaCl.
compounds
Na+ = positive ion
Salt, NaCl
Cl- = negative ion
See pages

3. Covalent Molecules Covalent share electrons. molecules
There is generally no order to the formation of covalent molecules.
These molecules clump together as solids, liquids or gases.
Covalent molecules are like a play-pit full of plastic balls.
Each plastic ball = 1 covalent molecule of H2O
molecules
Water, H2O
See pages

4. Naming an Ionic Compound
Ionic compounds are always composed of a metal and a non-metal.
The name of an ionic compound = positive ion + negative ion-ide.
For example, an ionic compound forms between magnesium and oxygen.
The positive ion is the first part of the name, magnesium.
The negative ion forms the root of the second part of the name, oxygen.
Add -ide to the end of the name to form magnesium oxide.
Non-Metal
Metal
Metal (2+)
Non-Metal (2-)
Magnesium oxide is used as a drying agent.
See pages
(c) McGraw Hill Ryerson 2007

5. You try… Calcium nitride What is the name of Ca3N2?
What is the positive ion?
Ca = calcium
What is the negative ion?
N = nitrogen
Drop the end of the negative ion and add -ide.
What is the name of Ca3N2 ?
Calcium nitride

6. Practice Problems

7. Names of Covalent Compounds
Covalent compounds, also called molecules, rely on the chemical formula to reveal the components of the molecule.
Covalent compounds are made up of two or more non-metals.
Names may reveal the components, but often they do not…
For example... The name of the compound C2H6O is ethanol
Another example is C12O22H11 which is Sucrose (table sugar)
See page 193

8. Naming Binary Covalent Compounds
Binary covalent compounds (two non-metal atoms) use a system of prefixes.
Write the most metallic atom (farthest left) first
Add -ide to the end of the second atom’s name
Add a prefix before each atom’s name to indicate the number of atoms in the molecule.
(Do not add a prefix to the first atom if there is only 1)
For example: CO = carbon monoxide, CO2 = carbon dioxide
What is the name of the molecule Si3P6?
Trisilicon hexaphosphide
See pages

9. You Try... Tetraphosphorus decasulphide What is the name of P4S10?
What is the most metallic atom?
P = Phosphorus
Add –ide to the end of the second atom’s
name
S = Sulphide
Add prefixes before each atom
4 Phosphorus = tetraphosphorus
10 Sulphur = decasulphide
What is the name of P4S10 ?
Tetraphosphorus decasulphide

10. Practice Problems