This afternoon the girls and I did a neat science experiment. I found it on Playdough to Plato (great name, isn't it?) If you have a few minutes, try this out with your own kids, or just on your own. I was able to find all of the supplies I needed at the Dollar Store or in my own pantry.
Here is what you'll need:
2 empty water bottles
teaspoon of sugar
two bottles of diet cola
packet of Pop Rocks candy
2 Mentos candies
In one of the water bottles pour about an inch of warm water and then dump in the entire packet. Swirl the yeast around a bit and then add the teaspoon of sugar and give it another swirl. Put a balloon over the mouth of the bottle and let it sit in the sun. It should take 5-10 minutes for the yeast to start bubbling and the balloon to begin inflating. You can explain to your kids that the yeast is a type of bacteria so it's actually a living thing. It's eating the sugar that we added and when it eats the sugar, it creates a gas called carbon dioxide which is filling up the balloon.
|The longer you leave the yeast going the bigger the balloon will get.|
Pre-prep the third balloon by using the funnel to pour in a packet of Pop Rocks. Pour out half of the soda. Put the balloon over the mouth of the bottle and dump in the Pop Rocks. You'll be able to hear the popping as the Pop Rocks release their pressurized carbon dioxide making gas which is filling up the balloon.
Pre-prep the fourth balloon by inserting the Mentos in it. Pour out half of the soda from the last bottle. Put the balloon over the mouth of the bottle and dump in the Mentos. The Mentos make a great catalyst causing the diet cola to release carbon dioxide gas which is filling up the balloon.
Once you have all four bottles set up and balloons inflating, it's a good time to compare your results. Which bottle blew up the balloon the best? Explain that each of these combinations create an invisible gas called carbon dioxide. The carbon dioxide fills the bottles and then moves into the balloons, blowing them up. Each of these chemical reactions produce a different amount of carbon dioxide. Which one made the most carbon dioxide gas? You can also make a connection between the bottles and our bodies and how we breathe out carbon dioxide which the plants use to make oxygen.
If you have enough of the supplies left, try doing the experiment again. Have your child predict if you'll get the same results or different. Have fun and happy inflating!