Blowing Up a Balloon

  • Fill your bottle ¼-½ full with water
  • Add 2 teaspoons of citric acid
  • Put the lid on the bottle and shake until the citric acid has dissolved
  • Put 1 tsp bicarbonate of soda into the balloon. You may need to use a funnel or have someone help you!
  • Put the neck of the balloon over the neck of the bottle.
  • Lift up the balloon so the bicarbonate of soda falls into the bottle.
  • Watch the balloon blow up!
The Science – You mixed an acid (citric acid) and an alkali (bicarbonate of soda) which made bubbles of carbon dioxide. When the bubbles popped the carbon dioxide got trapped in your balloon!


  • Open your balloon-copter.
  • Take the piece that has 3 little tubes sticking out of it. Find the 3 long propellers and stick one onto each tube.
  • Take the other small piece, that has a short nozzle on one side and a longer nozzle on the other side.
  • Stretch the neck of the balloon over the short nozzle.
  • Blow the balloon up by blowing through the longer nozzle. Pinch the neck of the balloon so that it doesn’t fly away.
  • Attach the long nozzle to the middle of the piece that has the propellers attached.
  • Let go of the balloon and throw it up into the air!
Here is Chemical Cress to show you – [embedyt][/embedyt] The Science – When the air comes out of the balloon it travels out of the 3 tubes that have the propellers attached. This causes the propellers to spin. When they spin the make a force called ‘lift’ which forces your balloon-copter upwards until your balloon runs out of air.

Popping Test Tube

  • Take the lid off your test tube.
  • Add ½ tsp citric acid.
  • Then add ½ tsp bicarbonate of soda.
  • Add 1 pipette of water and quickly put the lid on. Make sure you don’t hold it under your face just in case it pops before you are ready.
  • Hold it in front of you with your arm stretched right out.
  • If it doesn’t pop straight away, keep your arm stretched out and shake the test tube gently.
  • If you are quick enough, put the lid back on and see if it will pop again!
The Science – Just like with the balloon – You mixed an acid and an alkali which made bubbles of carbon dioxide. When the carbon dioxide filled all of the space in the test tube it pushed the lid off!

Rainbow Glasses

  • Put on your rainbow glasses and look out the window (never look directly at the sun) or at the lights in the room.
  • You should see lots of rainbows!
The Science – White light (that we get from the sun and lightbulbs) is actually all of the colours of the rainbow combined! The lenses in the glasses are made of something called “diffraction grating” that splits the white light into all of the rainbow colours.


  • Pour your slime powder into a pot or bowl.
  • Slowly add half a cup of water. Stir!
  • Using your spoon, or a stick, slowly stretch some of your slime out of the pot to see how stretchy it is.
  • Make sure to keep it in the bowl or pot, and away from carpets!

The Science – The powder is so absorbent it absorbs (soaks up) all of the water and sticks together to make slime!

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