In your kit you should have:
  • 1 bag of polymorph balls
  • A wax crayon
  • 2 growing animals
  • Pipette
  • Blanket picture
You will need:
  • Hot water in a mug (ask a grownup)
  • A spoon
  • Scissors
  • Cup of cold water
  • 1 x piece of A4 paper (it doesn’t have to be blank so scrap paper is perfect)
  • A few things you can use as weights e.g. pennies, pasta or paperclips


One of the big problems with plastic is that once it is made into something, it takes a lot of heat and energy to turn it into something else. Because of this, plastic is often thrown away and ends up in oceans which is bad for the animals that live there. Polymorph is a plastic that can be melted at around 70 degrees celcius which means you can melt it with hot water in your own home! It is really important that you get an adult to help you with this one because it involves very hot water.
  • Ask an adult to boil a kettle and pour the boiling water into a mug – like making a cup of tea without the teabag!
  • Ask the adult to pour all your polymorph into the boiling water.
  • Watch the polymorph and see it go clear!
  • Ask the adult to scoop the polymorph out with the spoon. It should be very squidgy. When they say it is cool enough to touch, but still squidgy, they can give it to you.
  • Mould the plastic as fast as you can into a shape of your choice. Let it go cold and it will go hard like real plastic!
  • If you aren’t happy with your shape, just ask the adult to drop it back into the hot water for you and wait for it to go clear again.
  • You can keep remoulding your plastic as many times as you like. When it has gone hard you can even colour it in with felt tip pens.

Hydrophobic picture

The word ‘hydrophobic’ means ‘scared of water’. Some materials are hydrophobic which means that water just runs off them.
  • Cut out the blanket.
  • Colour the whole thing with your wax crayon. Press as hard as you can and go over the blanket a few times to make sure the whole thing is completely covered in wax crayon.
  • Find yourself a toy or figure that will fit under your paper blanket. Maybe a LEGO minifigure or you could draw a stick figure on another piece of paper and cut it out.
  • Put your toy under the paper blanket.
  • Using your pipette, slowly drip some water onto the paper blanket. Hopefully, the water will run off the wax and your toy won’t get wet! Sometimes people coat clothes and shoes in hydrophobic materials so that they are waterproof. Ducks cover their feathers in hydrophobic oil so that they are waterproof too!
  • What else could you make hydrophobic?

Paper bridge

Some materials can be made stronger just by changing their shape.
    • Get yourself a piece of paper. A4 is a great size but any size will work and it doesn’t have to be blank. Rest your piece of paper on two different things of equal size like in the picture below. We’ve used two rolls of tape but you could use lego, pens – anything really!
    • Get your weights (you can use pennies, pieces of pasta, paperclips – anything that you have a lot of) and put them one at a time on the paper. How many can you put on before the bridge collapses?
    • Now, try folding your paper like in the picture below.
  • Try putting your weights back onto the paper. Does it hold more now?
Here is Chemical Cress to explain how/why this works – [embedyt][/embedyt] Growing animal Some materials are very good at soaking up water and can even grow! Take your growing animal and put it in a cup of water. Leave it overnight and by tomorrow it should have grown! Here is Chemical Cress to explain why this happens – [embedyt][/embedyt] Enjoyed this kit? Visit our shop for more weekly science kits.  

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