Do you remember lava lamps? I do! They were so much fun and this is a super easy experiment that you can do with your kids that teaches them all about the science behind the awesome colours etc.
This looks incredibly cool and the boys LOVED it, what’s more I loved it because it was so simple and all of the ingredients were things that I had in my home, so no ordering online or or trips to the shop.
Here is what you need:
- Water
- A clear plastic bottle or glass jar
- Vegetable oil
- Food coloring
- Alka-Seltzer (or other tablets that fizz)
I love crafts like this with such simple household ingredients.
Pouring is a great life skills for toddlers to learn and is fun for them too!
Pour water into the plastic bottle or glass jar until it is around one quarter full. Pouring water is a great practical life skill for toddlers to learn (it sounds silly I know but it is a great idea to encourage them to do it themselves).
The oil will automatically separate from the water, which makes it look really cool and Reuben was fascinated.
Pour in vegetable oil until the bottle is nearly full – again let the kids to this. I used a funnel for this because I didn’t want oil all over the counter.
Pouring from a normal jug makes more sense than trying to pour from the bottle, it’s too heavy for little ones and often ends in a huge mess!
Let the oil and water separate and talk to your kids about how and why this happens – it’s a great chance to explain science to young kids, though Reuben did just look at me like a headless chicken! So if you don’t know here is what is happening:
The oil and water separate from each other, with oil on top because it has a lower density than water. The food coloring falls through the oil and mixes with the water at the bottom then piece of Alka-Seltzer tablet releases small bubbles of carbon dioxide gas that rise to the top and take some of the colored water along for the ride. The gas escapes when it reaches the top and the colored water falls back down. The reason Alka-Seltzer fizzes in such a way is because it contains citric acid and baking soda (sodium bicarbonate), the two react with water to form sodium citrate and carbon dioxide gas. – Explained from the fantastic http://scienceforkids.co.nz.
Though Reuben chose yellow it showed up reasonably well when in blobs, I wouldn’t recommend it as it didn’t really make a difference to the bubbles at the final stage. Blue (like in the first picture) works great, as does red.
Add around 10 ml food coloring to the bottle (choose any color you like though Roo chose yellow and it didn’t show up as well because of the oil!)
Watch as the food coloring falls through the oil and mixes with the water.
By this point Toby had joined us so we all got to have a chat about how dangerous certain things were to put near our mouths. Its another angle of learning, which I love.
Cut an Alka-Seltzer tablet into smaller pieces (around 5 or 6) and drop one of them into the bottle, things should start getting a little crazy, just like a real lava lamp! I let Roo drop the tablet in, although we had a little chat about how dangerous they were.
Look at those bubbles!
When the bubbling stops, add another piece of Alka-Seltzer and enjoy the show!
This is one of the best science experiments for kids and so much fun – the best part is if you decide you want to make the lava lamp go again at a later date you just need to add more tablet.
Enjoy!
Harriet x
