Educating Risa

Here’s another simple science experiment to try at home. This one is so easy and safe to do, my 5- and 7- year old did it completely on their own. You’ll need 5 raisins (or, in our case, craisins, as that’s what we had in the cupboard):

A can of club soda, freshly opened and poured into a tall clear glass:

Ask the kids for their hypothesis as to what will happen when we drop the craisins into the club soda—will they sink or float? Note their hypotheses and then drop the craisins, one at a time, into the glass:

Observe. Do they sink? Do they float? Do they do BOTH?

Enjoy the dancing craisins show. They sink, only to have carbon dioxide bubbles build up on them and so are raised up. They hit the surface, the carbon dioxide bubbles escape into the air, and the craisin sinks again. Over and over the craisin makes its dancing journey. I was quite surprised at how vigorously they bounced around in the glass. See if the kids can explain why the craisins are dancing up and down.

Add a few more craisins (if desired). Be sure to ‘de-clump’ them if necessary:

Observe closely. Put your face over top to feel the carbon dioxide gas escaping (it’s actually spitting small water droplets at you as the bubbles break the surface):

Have fun!