Density
- Density is the measure of how close and how heavy are the particles of matter in an object. It is measured in kg/m3 or g/cm3 or g/mL.
| Density (ρ) = | Mass |
| Volume |
- Example of Density Rule
Q. A stone has a mass of 10 grams. When it is immersed in a measuring cylinder of water, the water level rises 5 millilitres. What is the density of the stone?
| A. | Density = | Mass | = | 10 grams | = 2 g/mL |
| Volume | 5 mL |
- Densities of Some Common Substances
| SUBSTANCE |
DENSITY
(g/mL) |
| Air |
0.002 |
| Feathers |
0.045 |
| Petrol |
0.7 |
| Water |
1 |
| Aluminium |
2.7 |
| Lead |
11.3 |
- Floating and Sinking
The density of water is 1 g/mL. Any substance (such as ice, petrol or oil) whose density is less than 1 will float. Any substance (such as lead) whose density is more than 1 will sink.
