1. A characteistic property
Density
A characteistic property

2. Who is that masked Molecule?
A characteristic property is something you can use to identify an unknown Pure substance.

3. Density to the rescue
If we know it’s density then we can determine which pure molecule it is.
Density is the mass divided by the volume.
D=M/V It always stays the same even if you have a lot or a little.
My mass is 42.5 grams
My volume is 42.5 ml
My density is 42.5g/42.5 ml= 1g/ml
Who am I?

4. Check you tables Air has a density of 0.00129g/ml Gasoline 0.69 g/ml
Fresh water 1g/ml
Parafifin wax 0.9
Glycerine 1.26g/ml
Aluminum 2.7g/ml
Iron g/ml

5. Tah dah! I’m Water 1g/ml If it is more dense than water it floats
If it is less dense than water it sinks.
Look back at the table name 1 thing that floats and 1 thing that sinks

6. Phases of matter and density
Mass is the amount of stuff or particles you have
Volume is the amount of space it takes up
Density is the amount of stuff in a space
Gases are less dense
Than liquids and
Liquids are less dense
than solids

7. This is one of the most important things you will learn this year
Density is a characteristic property
Density can identify unknown pure substances
Density is Mass divided by volume
D=M/V
The units are g/ml for liquids and gases
g/cm3 for solids