By Patty Rooks on June 29, 2019.
praxis@praxismh.ca@praxismedhat Woohoo! Summer has officially started for all of the students! I am sure you are all as excited as I am for a bit of a break to refresh and rejuvenate. As the kickoff to summer, this weekend many of us will be celebrating Canada’s birthday. I am crossing my fingers that the weather will be nice so we can get outside and enjoy the great holiday. In order to keep those young scientists busy, here is an activity that you MUST do outside. Let’s get started. *Remember to ask an adult before doing this experiment. Materials – outdoor location (preferably a sidewalk) – zipper baggies – tissue – liquid chalk (available at craft and discount stores) – baking soda – measuring cups – measuring spoons – cornstarch – vinegar – scissors Procedure 1. Take one tissue and separate the layers. Carefully pull the two sides apart and you will get a nice thin piece of tissue. Cut this in half. 2. Measure and place 30 mL (two tablespoons) of baking soda in the middle of the square of tissue you cut out. Fold this into a nice little package, tucking in all of the corners so that the baking soda stays inside. Set aside for now. 3. Measure 125 mL (1/2 cup) of vinegar and pour it into the baggie. Zip it up. 4. Measure 125 mL (1/2) cup) of liquid sidewalk chalk and pour it in with the vinegar. Make sure the bag is closed tightly, and shake it up a bit. 5. Add 30 mL (two tablespoons) of cornstarch to the vinegar/paint mixture. Squish it around until it is mixed up. 6. Make sure you are outside now – add the little package of baking soda to the bag. Zip it up QUICKLY and throw it out onto the sidewalk. 7. Stand back and observe. 8. If you did this on the sidewalk, you have a two in one activity – get out there and use the mixture to draw and write on the sidewalk. What is going on? I must confess that exploding baggies never get old! These experiments are a bit messy, but so much fun in the summer! Luckily for us, there is also some science behind this activity. When you mix the vinegar (acetic acid) and baking soda (sodium bicarbonate) a chemical reaction occurs and a gas called carbon dioxide is produced. This gas grows and grows and grows until the bag explodes sending your chalk mixture all over the sidewalk. Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. NOTE our NEW address: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403-527-5365, email: praxis@praxismh.ca. 27