Learning how to make a lava lamp will be a great activity for kids (and adults!) to get involved with, as they’re a unique and safe way to decorate your little one’s bedrooms.
But they’re also an exciting way to teach kids about density and chemical reactions, so they make a great science experiment for you try while the kids are off school as well.
What’s the lesson with lava lamps? The first lessons kids will learn from this experiment is about density (mass/weight). The vinegar sinks to the bottom of the container because it has a higher density than the vegetable oil, so it’s “heavier”. The second lesson is about chemical reactions. When the vinegar reaches the bottom of the container, it reacts with the baking soda and creates a gas called carbon dioxide. The carbon dioxide appears in the bubbles you see rising up the liquid to the top of the bottle.
Love this experiment? Test out out some of our other science experiments for kids to try at home, perfect for long weekends spent in the house or garden.
How to make a lava lamp
Many tutorials will tell you that you need to use an effervescent tablet, which are those vitamin tablets you dissolve into drinks. If you’ve got some going spare, then feel free to use them! This video will teach you how to make a lava lamp using effervescent tablets like Berocca.
But our tutorial doesn’t require anything apart from some basic household items and a few store cupboard essentials. If you don’t already have food colouring though, you can easily buy some online from Amazon.
You will need:
- Vegetable oil
- Food colouring
- Small cup
- Baking soda
- 1L bottle or cup
How to make your own lava lamp
1. Add the baking soda
In your 1L bottle or cup, add three tablespoons of baking soda.
2. Add the oil
Fill 2/3 of your bottle or cup with the vegetable oil, making sure it rests on top of the baking soda and doesn’t mix with it.
3. Mix the vinegar and the food colouring
In the other, smaller container add some vinegar and three drops of your food colouring.
TIP: Use different coloured food colouring with every new bottle, or mix some together (like blue and red) to create new colours that you often can’t buy. Or instead of food colouring, add some silver glitter!
4. Sit back and watch
Now, add your solution of vinegar and food colouring to the big 1L container, slowly, and watch what happens!
Place either your phone torch or a flat torch underneath you bottle to light up the bottom and achieve that famous lava lamp glow.