Rachelle, from A Little Monkey, recently sent some science projects to me to check out. I have to be honest, I am a little week in the science department. When she wrote about some microbiology/science projects I thought for sure I was in over my head, but I vowed to give it a try.
Rachelle sent me two experiments. I will share both with you, but we only tried one--I wasn't sure about the second experiment for my age children.
Here is Rachelle's first experiment, which we tried:
Take a packet of instant yeast & put it in 2 different water bottles (one w/ just warm water, the other with warm water and a sugar packet). Put a balloon on top of the water bottle. The bottle w/ the yeast and sugar will eventually have an inflated balloon b/c the yeast is eating the sugar and producing carbon dioxide as a by product thus blowing up the balloon. I usually describe this as the yeast belching and farting and this sends the kids into fits of laughter ;-)
I told the children pretty much the same thing: That the yeast was eating up the sugar and burping afterwards--then of course we all had to make burping noises loudly and laugh for hours! They were very excited to see the balloon rising though.
Here s Rachelle's second experiment if you would like to give it a try:
It is messy, but kinda neat, measuring lung capacity through water displacement. Take a tub (like a portable dishwashing tub) and fill it half way with water. Fill a gallon milk jug w/ water, and invert over the tub (with the mouth down into the tub of water to prevent leakage). Get some long straws and put them into the milk jug hole under the water. Have a youngster take a BIG breathe and blow out through the straw (the air will push water out of the milk jug and into the tub creating an air pocket inside the milk jug). The water displaced is the child's lung capacity (or at least the volume of air he/she blew out).
Thanks so much Rachelle for sharing some fun science with us!