Long ago, when I taught third grade, we started a hands-on science program. Teachers were provided with four kits per year that included a teacher’s guide and all the materials to teach the 8-week unit. Can you say FABULOUS! I mean, seriously, the first kit I received (I was teaching 5th grade) was called Microworlds. The kit included a microscope for every student. Every. Student. This was a game-changer for me.
It was purely wonderful to have all the materials I needed. Then I moved to third grade and also loved, loved, loved the kits we taught. My favorite one was about chemical testing. So, of course, I needed to add some chemicals to the STEM Lab! #ofcourse
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Projects for the STEM Lab
I knew I wanted to have a two-week unit for third graders to extend what they were doing in their classrooms. I needed to add something to it and we worked together to develop these projects. We also loved using our notebooks that first year to record all the results of our tests. So, what on earth did we try? Here you go:
- What are Chemical Changes?
- Testing Those Unknown Chemicals
- Elephant Toothpaste
- Instant Snow
What are Chemical Changes?
Third graders need a lot of work with this question. Our tasks included sorting task cards that each described a chemical or a physical change. They worked in teams to read the task cards and categorize the descriptions. They got a lot of them wrong! But, that is okay. This preliminary activity got us ready for the first experiment. It’s the Balloon Test!
I gave each team a bottle with a mystery liquid in the bottom. The balloon had a mystery powder in it. They recorded their predictions about what would happen when those two items were mixed and then lifted the balloon and poured the powder into the liquid.
There were lots of ‘ohs’ and ‘ahhs’ at these results. The balloons all over the room began to fill. The mixture of those two items caused a chemical reaction that creates a gas- which fills up the balloon. This led us to create a chart of the requirements for a chemical reaction. The first is: a new substance is formed. Now, I have mentioned that we were recording information (like predictions) and making charts. We did this in our science notebooks.
For the tasks we were completing I created templates for students to cut, write on, and glue into their notebooks. This included places to predict and write about results. We also used extra pages to make our own charts.
You just have to love those brightly colored notebook templates. #astrobrightspaper
We moved into doing more testing. Students had already tested some powders in their classrooms, so I created new powders they had not seen. I used flour, ground chalk, baking soda, salt, and baking powder.
The task was to drop water on each of these powders and record the results. Then we repeated it with drops of vinegar. Which one had a chemical reaction?
The baking soda fizzed with the vinegar- do you think they make the connection back to the balloon and powder task we started with? Yes, they did- how exciting is that!
TIP: We use toothpicks to stir our liquids with the powders. We always use a different toothpick for each powder. This is important because you do not want to contaminate your results!
TIP: If you ever try an experiment like this you need to use waxed paper. We place a piece of waxed paper on our trays and do the testing on it. It makes cleaning up really easy. You just fold up the corners and make a trash ball to toss. (Well, not literally!)
This is an exciting demonstration. We tried the card sort activity again before we completed this experiment. The students got most of the answers correct the second time! Elephant toothpaste is a chemical reaction demonstration during which you mix yeast and peroxide. I do this one as a demo for a few reasons.
- It is too expensive to create enough materials for teams to do.
- It involves precise mixing and the yeast has to be warm.
- It also makes a big mess. I’d rather just clean up one mess.
The tray in the photo has the main items you will need to try the experiment. And you need a higher percentage peroxide. I bought mine at a hair-styling salon. (Think about that!)
You can see in the progression of photos above that the reaction is extreme and it happens immediately. And it keeps going for a while. I always place the bottle on a tray to help catch the overflow! The green color of the water just makes it more spectacular. (It’s food coloring!) When this demonstration is over we talk about whether it is a chemical or physical change.
The Last Task- Instant Snow!
Instant snow is a powder that is commonly found in diapers. It is highly absorbent. (Think about it.) Each student gets a small cup with about a teaspoon of the powder. They also get a cup with water in it. At my signal, they all pour the water into the powder and watch to see what happens.
You can see the progression above. In a matter of seconds, the powder overflows the cup! Third graders are so excited by this. So, is Instant Snow a chemical change? The last task for the students is to write what they think and back up their thinking with scientific reasons. They use all they have learned and the chart we made that lists all the ways a chemical change can be recognized. Most of them will say Instant Snow is a chemical change. By the way, the company that makes the powder says it is a physical change. It reverts back to powder form over a short period of time- a chemical change does not do this!
This amazing set of lessons is available in my Teachers Pay Teachers store- all the work is already done for you. It includes tons of tips and the notebook templates.