This is going to be a busy week! While the test is on Friday, I am devoting today, tomorrow, and Wednesday to hands-on science. Today's was a review/exploration of the fossils section of the unit while the other two days will cover Earth changes (erosion and deposition, weathering). First, given that it is a Monday, we covered literacy both with independent reading and small group instruction. Then, we did the warm-up.
Today's experiment covered fossils and it was a two-part activity. The first part was to simulate the formation of an imprint. An imprint is the mark of a once-living organism embedded in a rock sample, usually a softer one. It can be a foot print or the organism itself that gets covered with dirt and becomes sedimentary rock. Over time, it gets revealed through weathering and erosion.
We simulated an imprint of an octopus. This is what we did:
Each group was called up one at a time. Each was given a plate, two toothpicks, and a gummy octopus. Once they got their materials, they came to me and I poured a small amount of blue candy melt onto their plates. Upon returning to their seats, they allowed their candy melt to harden. As it hardened, they took their gummy octopus and pressed it into the candy melt and held it long enough to form an imprint. After taking it out, they inspected it. If it was good, they ate the gummy octopus and waited until the next step.
Once all of the imprints were ready (and the gummies eaten!) I went around with a butter flavored nonstick spray and hit each imprint with a short blast of the nonstick coating. This was to make the second part of the activity easier.
The second part was to make a cast mold of the fossil imprint. Now that we had the hardened fossil imprint of an ancient octopus, we pretended that we were paleontologists who discovered the imprint of a prehistoric octopus. The task: make a cast mold of the imprint in order to have a three-dimensional model.
How it was done: the students were again called up by groups to bring their plates with the imprint on it. Since the imprint had blue candy melt, I then poured a small amount of hot pink candy melt into the imprint that was sprayed with a nonstick coating. When they returned to their seats, the students again had to wait until the pink candy melt started to harden.
These are the tricky parts: once the candy melt has hardened enough, the students were to place their two toothpicks into the pink part and waited until it hardened completely. The important part was to not push the toothpicks too far down into the blue candy.
Once it was fully hardened, they were supposed to use the toothpicks to carefully remove the cast from the imprint. Some students were more successful than others but overall it was a great activity.
Unfortunately, the second part of the activity did not work. For the first class, there wasn't enough time for the pink candy melt to harden. For the second class, there was time enough (lunch and recess gave us an hour) but the spray did not prevent the two from fusing.
However, while I am disappointed that it didn't completely work, I do not regret doing it. Being that ours is a STEM school, things not working are not mistakes but opportunities to reflect on what went wrong and to think about better ideas.
I think what would have worked is if I had a small refrigerator/freezer in my room. But, even if I did, it would have been too small for the number of students unless I used a smaller container.
Tomorrow the focus will shift to social studies though we will still do a hands-on activity (erosion and deposition).