C

This week’s topic was chemical engineering. We started the class by explaining what chemical engineers do and presenting and giving examples of the 3 states of matter: solid, liquid, gas. We then played short game that clarified how molecules of objects act during the 3 different states of matter. We had the students stand together in middle of the room to represent the solid state. Then we had 5 students leave, giving more space for the students to move freely to represent the liquid state. Then for we had five more students leave and have the rest of the students move around freely to represent the gas state of matter.

Our main activity of the day was making goo out of cornstarch, water, and green food coloring. We told the students that they were chemical engineers hired to create a substance that is both liquid and solid at the same time. The goal is for the students to mix the water and cornstarch in appropriate proportions so that the mix in their bag was solid yet watery. For this activity, we handed each student cornstarch on a Ziploc bag and a cup with a bit of water. We asked the kids to add the water in the bag and mix the two ingredients in the bag. We purposely did not give the students the appropriate amount of water so that they can experiment on their own how much more water they would need to add. We asked the students to use straws to add water one drop at a time and mix constantly. Those who think they needed more cornstarch were also able to ask for more from us.

Regardless of all the mess that was created the activity worked out pretty well and the students were very enthusiastic. A lot of the students were very impatient and ended up adding a lot of water at once instead of drops at a time; therefore, we had a lot of kids with very watery mixes in their bags. A lot of the bags also started leaking. However, asking the kids to keep their work inside the bags definitely lessened the mess that was created. In the end the kids learned how to estimate the amount of water or cornstarch they would need to add in order to get the appropriate liquidy solid mix that they want. Most importantly, they had a lot of fun experimenting and creating their goo.