This activity kept my 2 year old entertained for AGES. It was cheap and easy, and I bet you have all the things you need in your house already!
We used :
2 cups of Baking Soda (use as much or as little as you want though!) 2 cups of White Vinegar (separated into a number of bowls) A pipette (okay, truth be told we couldn't find ours, so we used a Vicks Stuffy Noses sucker thingy) Food Colouring A plate or tray
Spread the baking soda out over a tray - the bigger the tray, the more baking soda you can use. Spread it quite thinly if possible.
Mix the food colouring into a few bowls of white vinegar.
Use pipette to drop the coloured vinegar onto the baking soda.
It will fizz and 'erupt'. For older kids you can take this further and talk about the chemical reaction, why it occurs, how it occurs. Try dripping water on the baking soda to show that it's the vinegar that's making it happen.
Younger kids will just love the colours mixing together, and the way the baking soda fizzes.
There you have it! A quick, fun and easy science experiment for kids of all ages!