1. Density

2. Which balloon falls, which one rises?
Helium
Radon
WHY?

3. Density
Take a look at the two boxes below. Each box has the same volume.
If each ball has the same mass, which box would weigh more? Why?
The box that has more balls has more mass per unit of volume.
This property of matter is called DENSITY.

4. What is density?
Density is the amount of mass in a volume. It tells us how tightly matter is packed together.

5. You can make an object more dense by decreasing the volume.
What is density?
You can make an object more dense by decreasing the volume.

6. What is density?
You can make an object more dense by increasing the mass, but keeping the volume the same.

7. How do objects float?

8. How do substances float?

9. What do you think will happen?
How do objects float?
Same volume of liquid
Same size can
What do you think will happen?

10. Density
Density is the mass of one cubic centimetre (or cubic metre) of a substance.
So for example, gold has a density of 19.3 g/cm3.
This means one cubic centimetre (cm3) of gold has a mass of 19.3 grams (or one cubic metre of gold has a mass of kg)

11. Can you copy this please!
Density
mass
volume
Or using the formula triangle; m
ρ x V g
Density =
g/cm3
cm3

12. Density of regular shapes
volume = length x width x height
density = mass
volume
mass using a scale
height
width
length

13. Density of liquids density = mass volume Volume Mass of liquid
Mass of liquid and cylinder
Mass of cylinder
density = mass volume

14. Density of irregular shapes (1)
mass
Difference in level gives the volume of the shape
Density = mass/volume

15. Density of irregular shapes (2)
mass
Displacement can
volume of object
Density = mass/volume

16. Float Density Sink Force Temperature Particles Volume
Explain, using the key words below, why there is a temperature requirement for competitive swimming pools.
Float Density Sink Force Temperature Particles Volume