Science Smarts: Spook-tacular science

By Medicine Hat News on October 5, 2024.

As I was driving home the other evening, I had a chance to see some of the amazing Halloween displays in the city!

They are absolutely amazing – from the colourful pumpkins, to the giant moving skeletons in the front yards, I am sure there is something to scare everyone as this day fast approaches.

In keeping up with my theme of Halloween Science, this week, I have something that could make things easily disappear. Let’s get started…if you dare!

*Remember to ask an adult before doing this experiment.

Materials

• cornstarch

• large plastic tub (size will depend on what you want to make disappear)

• water

• spoon

• science helper

• plastic toy animal

Procedure

1. Measure ¼ cup (60 mL) of cornstarch and pour into a large plastic tub.

2. Measure ¼ cup (60 mL) of water and add to the container.

3. Stir well with a spoon

4. Stir the mixture with the spoon.

5. Working with your science helper, pour a little bit of the mixture into your hand. It will be very runny.

6. With your finger, touch the liquid.

7. Observe what happens.

8. Push down on the liquid in the container.

9. Observe what happens.

10. Place the plastic toy animal in the mixture.

11. Gently push on it.

12. Observe what happens.

What is going on?

Did you know that matter takes the form of solid, liquid or gas?

However, solids, liquids and gases can be mixed together in interesting ways to create something else…. When one substance dissolves or disappears completely into another, the result is called a solution.

I bet you thought that was what you were making here! The cornstarch and water mixture is not a solution, however. It is a slightly different mixture called a colloid.

A colloid is a mixture of tiny particles of one substance scattered evenly throughout another.

In this case, the cornstarch particles are scattered evenly throughout the water.

 As you observed, colloids can change form under pressure. In this activity, when the mixture is in the container, it appears to be a liquid.

But when your science helper touches the solution, the touch puts pressure on the mixture.

The pressure forces the cornstarch particles together and the mixture becomes solid. When pressure is released, the mixture returns to its original liquid form.

When you place the plastic animal on the mixture, it will slowly sink and disappear. What else would you like to make disappear?

It is official – bookings are now being taken for the Science Fair 101 Program!

We are here to help support educators and students develop award winning science fair projects. It is up to you as an educator how much or how little support you require; from introducing the scientific method, to ensuring your students have all of the steps required for their project to assisting with an in school science fair; we can have your students prepped and ready for the 50th annual Regional Science Fair on March 22, 2025!

Space is limited so please book early.

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. Address: 12 826 11th Street SE, Medicine Hat, AB, T1A 1T7 Phone: 403-527-5365, email: praxis@praxismh.ca.

39
-38