Science Smarts: ‘Wow’ the students

By Medicine Hat News on September 2, 2017.

Welcome back to school all educators and students. Where did the summer go? I can hardly believe that the countdown to the first day of school is here; two more sleeps. There are going to be a few groggy eyes and tired bodies on the buses Tuesday morning, of that I am sure. This week, I thought I would share a little something to ‘wow’ the students in their seats and kick off a great year of science! Let’s get started!

*An adult needs to do this experiment with you.

Materials

– food colouring

– package of yeast

– warm water

– measuring spoons

– measuring cups

– empty cup

– stir stick or spoon to stir with

– large plastic flask or empty large soda bottle

– peroxide

– dish soap

– safety goggles

– baking pan

– flat empty counter or table to work on

Procedure

1. Find a good place to work as this experiment could potentially make a mess! Outside would be perfect or a good sturdy counter will work too.

2. Put on your safety glasses.

3. Place the flask on the cookie sheet and set aside for now.

4. Measure three tablespoons (45 mL) of warm water into the empty cup.

5. Measure one tablespoon (15 mL) of dry yeast to the warm water. Stir it well and set aside for a minute or so.

6. Measure 1/2 cup (125 mL) of hydrogen peroxide and carefully pour it into the flask.

7. Add a few drops of food colouring of your choice. Swirl it around.

8. Squeeze three large squirts (I know such an exact measurement, but it does not need to be precise) of dish soap into the peroxide mixture.

9. Have everyone stand back and slowly add the yeast mixture to the peroxide mixture.

10. Watch what happens.

11. Clean up your mess!!

Explanation

I call this experiment elephant toothpaste because it looks like toothpaste being squeezed out of a tube and big enough for an elephant to use — it should foam up and squirt right out into the air!

There is a bit of a complicated chemical reaction occurring in this pretty cool experiment! Let us look at this simply É basically you start with peroxide and a bit of soap. You add a catalyst to this mixture. As a result of this you start breaking down the peroxide into two of its components; oxygen and water. What you end up with is water and soap and a ton of tiny bubbles as a result of the oxygen being released.

Did you know that you should read the percentage of peroxide you use as there are varying strengths? Three per cent, 12 per cent, and even higher. Look around at different stores to see what you can find. The stronger the peroxide, the larger your reaction! Be careful, though, and follow all safety rules to keep your science fun and safe.

Educators, do not forget to book your hands-on Science Learning Kits early so you do not miss out on having them to use in your classroom. Do not forget to call us for all of your science needs this school year; we are excited to be kicking off a great year once again in southeastern Alberta!

Patty Rooks is senior scientific consultant at 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.

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