Watch this short video to learn how to make your own density tower.

Items you'll need:

• Tall glass
• Milk
• Water
• Washing up liquid
• Honey
• Vegetable oil

Science behind the experiment

Instead of mixing, the liquids should stack up in layers. This is because the liquids have different densities.

Materials have different densities, this changes if the same volume of each have different weights. In your tower, if you have used the same amount of each liquid, they will stack up from most (at the bottom) to least dense (at the top).

Key Terms

• Density – a measure of mass per volume.
• Liquids – a liquid is one of the states of matter. The particles in a liquid are free to flow, so while a liquid has a definite volume, it does hot have a definite shape.
• Volume – is the quantity of three-dimensional space occupied by a liquid, solid, or gas. Common units used to express volume include litres, cubic meters, gallons, millilitres, teaspoons, and ounces.

Activities and Questions

Add salt to your water, does salt change the density of the water?

Try other liquids that you can find, do different types of oil have different densities?

Try adding solids into the tower, e.g. Rice Krispies, a paper clip, LEGO brick, a lentil. Will they float in different layers?