Liquid or solid?

I have been searching in vain for appropriate activities to do in a wet city with the children. San Francisco is such and 'outdoors' city that most of its attractions and adventures feature being outside. And to top that, ALL the museums are closed on Mondays - and today is monday, and its raining and the girls are on holiday from nursery for a week together with Owen.

Then I found 'Gak'. So much fun......messy, but fun. Defiantly not an activity for when Dave is at home!
There are lots of variations on this theme but this seems to be the easiest and more of a 'store cupboard don't need to leave the house' kind of recipe.

You will need:

• to be calm in body and mind before embarking on this project. Its fun science but be prepared.
• cornstarch
• warm water
• food colouring (optional)
• a plastic container and spoon for mixing
• a BIG plastic tablecloth

Start by measuring 1 cup of cornstarch into the plastic container.

Gradually add up to 1/2 cup of water to the cornstarch. You can mix this with a spoon or hands!

The consistency of the mix will go from a powder to a smooth liquid that is not too runny. It needs to be able to run smoothly but slowly.

Add a few drops of food colouring and mix through.

And then have lots of messy fun!

'Gak' turns from a liquid to a solid when touched and then back into a liquid again.  You can form it into a ball and, if the consistency is right, you can snap it. The photos do not do it justice as it always looks like a liquid but it was amazing.

We could pick it up and mold it into a ball and then when it was dropped on to the mat it turned into liquid again. Apparently the scientific word is a polymer.

Owen has thought of loads of uses for it and games to play in the garden with friends, even tricks for halloween. We have also carried on our science experiment by mixing dyes together and then coloured 'Gak' to see what different colours we can make. We even have a pot in the fridge to see what effect temperature has on the mix.

The mixture will store in an air tight container for up to two weeks. If it dries out then just add a little more water and mix well. If you spill it in unwanted places then just let it dry and brush it away. It returns to a powdered form.

I hope you have enjoyed this and that you try it too. So much fun....

Love Jo