A fish tank
A water glass
Fill a fish tank or other large container about 2/3 full of water. Invert the drinking glass and push it into the water trapping air inside the glass. Students will easily observe the trapped air inside the inverted glass.
The true value of this experiment is to slightly tip the glass to allow a bubble of air to escape and float to the surface of the water. The air bubbles prove there is air that has volume within the glass. The air, as it moves out of the glass, is replaced by the water proving air takes up space.
- In small lab groups, two carefully chosen containers such as a large glass baking bowl and a shot glass can be used.
- As with other science inquiry experiments, I suggest you do not reveal the objective of the lesson too soon. Ask students to observe the natural phenomena they see and comment on their observations. With proper questioning, a teacher can lead the students to find the true objective of the experiment. As always, pull the knowledge from the students - Never, ever tell!
- Key Questions to Ask Students
Look at the empty tank. What is inside? (Response is usually 'nothing')
What is inside now? (After filling the tank with water)
How is water different from air?
Does water take up space?
Does air take up space
What is volume?