OK, this will be messy, so before we go any further with this experiment make sure an adult is there and you do it OUTSIDE!

To celebrate the new series of RTÉjr's science show for kids Let's Find Out, made with our friends at the SFI, top scientists Amy and Mark have some cool experiments for you to try. They're all to help Zoom understand the science around us.

Watch the show now on RTÉ Player!!

Here, Zoom puts too much press on a tube of toothpaste and makes a mess so she wants to know all about pressure. Press play up top and have fun!

Aoife and Joseph stay outside where they can use pressure to make a fizzy eruption!

For this Fizzy Cola and Mentos experiment you will need adult supervision.

Teachers can use the lesson plan here...

You will need:

  • A bottle of cola (2 litre works well and diet is less sticky)
  • A packet of mentos sweets
  • A geyser tube with adaptors

What to do:

  • Place four mentos mints in the geyser tube. Make sure each one sits flat on top of the other.
  • Place the cap on top.
  • Place the bottle of cola flat on the ground, outside and in an area that is safe to cover in cola.
  • Remove the lid from the cola bottle.
  • Carefully screw the geyser tube onto the top of the cola bottle.
  • When you are ready, release the mentos into the cola bottle, by pulling out the red switch on the side of the tube
  • Stand well back and see what happens.

The science bit:

Did you get a really big eruption of cola? That is because the cola is packed full of a gas called carbon dioxide, it makes the bubbles when we pour the cola. But inside the bottle, that gas is usually dissolved in the cola.

The mentos have tiny dimples or pits on their surface, just the right size and shape for the carbon dioxide to form bubbles. It is called nucleation and all the carbon dioxide that is dissolved in the cola forms these tiny bubbles all at once.

Those bubbles get trapped in the cola and create lots of pressure, so much so that it shoots that bubble filled cola into the air in one big eruption.

Click here to see all the experiments from the series!