One of the activities we do over and over again is making a lava lamp. These are great for parties or taking into the classroom and are reusable!
They are a safe, exciting and visual way to introduce chemical reactions to children.
You can see the full instructions for how to make lava lamp here, and this video shows how easy it is.
lava lamps are quite material heavy, but you can use them over and over again.
Try using effervescent vitamin tablets instead of alka seltzer, these are usually a bit cheaper.
What happens if you use half a tablet? Or two?
Once the reaction has finished, try gently tipping the bottle on its side. What do you notice?
Alka seltzer is made of citric acid and sodium bicarbonate which reacts with the water to form carbon dioxide gas and Sodium citrate. It is the bubbles of carbon dioxide bubbles that carry the coloured water into the oil.
NOTE – Please supervise the use of alka seltzer and effervescent vitamin tablets.
Other experiments you might like