Make your very own Blast Lab toy bazooka!

What to do:

1. Stand the crisp tube on a table with the lid facing up.
2. Place the film canister (lid facing up) on top of the crisp tube, in the centre of its lid.
3. Tape the canister into this position until it's completely secure (but make sure you can still open the film canister's lid).
4. Now dip the film canister (with crisp tube lid attached) into the bowl of water until the canister is half filled with water.
5. Put the crisp tube lid back on the crisp tube - be careful not to spill any water out of the canister.
6. Add half a Vitamin C tablet to the canister and put the lid on quickly.
7. Now aim the canister away from your body and wait.
8. The lid of the canister should soon pop off and fly through the air.
9. Try making two of these bazookas and compete with a friend to see whose lid can fly the furthest.

The reason the lids are popping off is all down to what is in the tablets.

Although the tablets have Vitamin C in them, obviously, they also have a little bit of acid and a little bit of alkali. This acid and alkali are kept separate in the tablet but when the tablet is put in water they dissolve in to the water and so they mix together. When the acid and alkali mix they make carbon dioxide gas. And it's this carbon dioxide gas that builds the pressure up and up in the canister until eventually the pressure becomes too much for the lid and it pops off - flying through the air.