Monday, 13 August 2012

Elephant Toothpaste!

This was an impressive activity for the children and one that they enjoyed very much. I got the original idea from Preschool Powol Packets.

2 tablespoons warm water
1teaspoon yeast
Half a cup of hydrogen peroxide (at least 6%) - I ordered mine at Lloyds the chemist
Few drops of food colouring
Squirt of washing up liquid

Put the tablespoons warm water in a container and swirl together with the yeast for a few moments (this is the catalyst).

Put the hydrogen peroxide, food colouring and soap in a large plastic bottle on a tray (to catch the bubbles). Then add the yeast mixture and watch!

The resulting foam is warm and safe to play with, being just oxygen, water, soap and food colouring.

We did it twice, once with a little squirt of green food colouring which didn't really show up and once with a rather larger squirt of red food colouring - I rather regret the red food colouring! 

The hydrogen peroxide, food colouring and washing up liquid in the bottle ready to go.
Yeast and warm water in the small pot - funnel for adding!
Love the expressions of wonder!
"It looks like a waterfall Mummy!"
"It's warm!"
Playing in the foam - this is before they started spreading it everywhere!

My children loved the bubbles and ended up rubbing the foam all over the chairs, table and themselves (I had to strip them fairly early on!).  By the time I put them in the bath they looked like they were suffering from some sort of all over body rash from the red version! The Eldest, having covered her chair in slippery bubbles, then managed to slip off and caught herself a right whack on her leg which came up with some impressive bruising poor lamb.  Just what she didn't need on top of being ill.

Bruising on The Eldest's leg almost a week later!
When the children are older, we can extend the activity by discussing the chemical reaction and the fact that it is exothermic, although they did already notice that it was warm.  They wanted to do it again and again, but sadly I only had one bottle of hydrogen peroxide, must order more!

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