You will need

• 3 Glass jars (empty and cleaned)
• 3 Marbles (cleaned and dried)
• If you don’t have marbles, use small rocks instead.
• Water
• Vegetable oil, for example olive oil or sunflower oil
• Syrup or honey
• Cooking oil and syrup or honey can still be used or eaten after this experiment.

What to do

1. Fill each glass jar with a different liquid at least half full. Make sure that the liquids have the same height in each jar.
2. Drop a marble into each one and observe how fast the marble falls through the liquid inside.
3. The slower the marble falls, the higher is the viscosity of the liquid. Which liquid in this experiment has the highest and which the lowest viscosity?

Background

It takes much longer to pour syrup into a glass than to pour water. This is because syrup has a high “viscosity”. This means that it does not flow easily. The higher the viscosity of a liquid, the slower it will flow.

You can test the viscosity of a liquid by dropping a marble into it. The slower the marble falls, the higher is the viscosity of the liquid.

You can watch this experiment as a video here: