We started off by pouring a packet of yeast into a bottle of water and shaking it for a while. Then, we divided the yeast-water into test tubes. After that, we poured sugar into one of the test tubes and left the other without. Last, we stretched a balloon over the top of each tube and moved on.
For our second experiment, we each got a plate and some flour. We poured yeast and sugar onto the flour and mixed them with our hands. Second, we poured some water onto our little pile of stuff and clumped it together into a ball of dough. Then, we took a straw and dug it into our ball, marking where it came up to on the straw. After that, we set the straw down and went out into the hall.
Last time we had science class, only half of us got to ride the hovercraft, so now the people who didn’t would get a chance. I stood in the “already rode” line and watched the craft float from one end of the hall to the other.
When we got back, the dough was halfway to the top of the straw. That was because the yeast gives off carbon dioxide while eating the sugar in the dough, pushing the clump up the straw.
The balloon over the sugar-yeast-water test tube were so inflated, I wasn’t sure if it was going to stay on there or not! That was also because of the carbon dioxide.
The teacher said that next time we were going to the park for class, so we had to remember to remind our parents. Can’t wait!!