We have enjoyed our first science club.  We made elephant toothpaste to investigate chemical reactions. The children followed step by step instructions and had no idea what would happen.  We mixed hydrogen peroxide with food colouring and washing up liquid. Next we mixed live yeast with warm water and stirred. After that we added the yeast mixture to the hydrogen peroxide concoction and waited in anticipation for a reaction.
The science behind the fun
The yeast and water mixture together acted as a catalyst (something that speeds up a chemical reaction in another substance , while remaining unchanged itself. When we added this to the bottle it made the  hydrogen peroxide break down into oxygen and water. The washing up liquid trapped the oxygen in bubbles to create the foam. Just a small amount of hydrogen peroxide will create a lot of oxygen, so you get lots of bubbles making the toothpaste almost explode out of the bottle!
Check out next weeks’ club to find out what we get up to then!