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Student Activity - Density
Activity idea
By the end of this activity, students should understand:
- All matter is made up of particles.
- Density is a measure of how closely these particles are packed together.
- The tighter the packing, the more dense the material.
- Density is measured in units of mass per unit volume.
Instructions
What you will need:
- blocks of wood (preferably cubes)
- bocks of plastic
- blocks of metal
- a book
- ruler
- scales
Instructions
- Rank the objects in the order of most dense to least dense.
- Using the ruler, measure the length, width and height of the objects to the nearest centimetre (cm).
- Use these measurements to calculate the volume of the object. (This will give the volume in cubic cm).
The formula is:
Volume = Length x Width x Height
- Weigh each object to the nearest gram (g).
- When you have recorded this information, calculate the density of each object.
The formula is:
Density = Mass/Volume
- Now rank the objects in order of the densest to the least dense. How close were you to your original ranking?
Thought questions and discussion
- Density tells us something about how tightly packed the particles are. Which object would be the densest of the ones you measured?
- The density of fresh water is very close to 1g/cm3. Objects that are denser than water will sink. Those, which are less dense, will float. Group your objects into those that will sink and those that will float. Test out your ideas to see if you are correct.
