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WATCH | Teach kids about science with this homemade lava lamp!

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A cool lava lamp experiment for little scientists. (Wavebreakmedia/Getty Images)
A cool lava lamp experiment for little scientists. (Wavebreakmedia/Getty Images)

Being stuck at home during lockdown doesn't mean your kids can't learn. 

From a very young age you can start introducing your kids to the fascinating world of science, whether it's with cornflour and water to make slime or water and oil in this lava lamp experiment.

They'll love playing and watching the substances react and the best part is, you have all the ingredients you'll need in your kitchen.

Check out the video below and scroll down to read the science behind it all. 

Ingredients and tools

  • Water bottle
  • Water (we used about 1/2 cup for a 375ml bottle)
  • Vegetable oil
  • Food colouring
  • Effervescent tablets

How it works

Okay, there are two very important scientific principles at play here: density and polarity.

Density refers to how compact a substance is or how much of it can fit in a particular space. Think of cramming a lot of people into a small room. Because they’d be packed tightly in a small space, that would be of high density, if you will.

In substances such as the water and oil used in the experiment, densities differ and the water is actually more dense than oil because it has more molecules packed tightly together.

As such, the substance that is more dense sinks to the bottom. That’s what you’re seeing when the two separates.

That being said, the two would eventually mix if it weren’t for polarity. Polarity refers to having positive and negative charges that attract each other, much like you’d find in a magnet.

But while water molecules have positive charges, oil molecules are non-polar, which means they have no charges to attract themselves to. So water and oil don’t mix.

Now, the thing about substances though, is that they can change forms.

Think about what happens when you apply heat to water. Your liquid turns into a gas and evaporates, right? Well, in a lava lamp with a light or heat source attached, the same thing would happen.

The denser substance would become less dense and begin to rise, which is why you start seeing the particles move around. 

In our experiment, the effervescent tablets also reacted with the water – our denser substance – to produce carbon dioxide gas bubbles with stick to the water molecules.

And because they’re less dense they rise and you’ve got yourself a lava lamp, before the gas bubbles pop and the water sinks back to the bottom.

Pretty cool, huh?

Here are a few cool things you can add to your homemade experiment with the kids:

Tips and tricks

  • The more tablets you use, the faster the reaction will happen and the more bubbles you’ll see.
  • Just as you can use any food colouring you want, you can also add other ingredients such as glitter. The kids will love the sparkly finish!

Enjoy!

Try out this lava lamp experiment and send us your comments and pictures about how it wen

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