So, I have been a terrible blogger this past month. I was traveling several weeks ago when the blizzard hit the northeast and ended up snowed in elsewhere, without some of my blogging necessities. When I was finally able to return home, I started having a Lyme flare that made it difficult to put a lot into bogging. Now, I am ready to get back into the swing of things and, to make up for lost time, I want to share one of my most favorite science lessons… exploding paint bags! There are so many creative ways to teach matter but this is by far the most fun for students.
When I was the Education Director for a children’s museum, I performed this activity frequently when teaching matter. When I returned to the classroom, I very much wanted to do it with my students but struggled with the cost. At the museum, I had a grant that enabled me to buy some pretty expensive materials such as powder tempera paint and individual canvases for students. I experimented with some inexpensive household items and found a way to replicate the experiment with relatively little cost. All you need is snack sized Ziploc bags, baking soda, food coloring, vinegar, plastic spoons, small dixie cups, and bulletin board paper. If your school does not allow you take bulletin board paper for classroom use, try your local newspaper. My local newspaper gives me large spools of left over paper for free.
Once you are ready, this activity is fairly easy to execute. Some years, I have given students their own sheets of paper to work on and, other years, I have rolled out a giant sheet of paper to make a class picture. I allow students to make about 2-3 bags each. To make a paint bag, put 2 scoops of baking soda into a snack size Zliploc bag (if you use a larger size bag, the gas does not always expand enough for the bag to pop— In the pictures, I had to tie a sandwich size bag in half because I ran out of snack size bags!) and zip the bag half way closed. Then, fill the dixie cup a little more than half full with vinegar. Put a few drops of food coloring into the vinegar and stir to mix it evenly. It is important to perform the next step quickly. Pour the liquid into the bag with the baking soda and zip the bag closed as quickly as possible. Sit the bag down on top of the paper and step back. The first time I ever did this activity with a group of kids, I did not step back fast enough and the paint bomb literally exploded in my face! My students thought my purple face was hilarious but it was not fun washing it out of my eyebrows and hair later!
When you are finished with the fun and the pictures are drying, talk to your students about how each phase of matter was represented in this activity. By mixing the solid (baking soda) and the liquid (vinegar) a chemical reaction occurs that creates a gas. As the gas molecules expand, they can no longer be contained in the bag and cause the bag to break open.
Lately, I have been trying to compile all of my science and social studies units for Teachers Pay Teachers and this week I posted my unit on Matter. The paint bomb activity is just one of many fun, S.T.E.A.M. (Science, Technology, Engineering, Art, & Math) based activities included in this unit. If you are interested in learning more, click the product image featured below.
If you get to teach matter this year, I hope you will try this activity! Your students will seriously love you for it and, while it is messy, you will have fun too!
One other note… I have a super special freebie I am working on! Help me reach 200 followers this month and I will post it to my store March 1! Thank you for your support!