An engaging science experiment is just a few household items away. The Canadian Association for Girls In Science shares their top science activities for kids to try at home.
The Canadian Association for Girls In Science (CAGIS) is an award-winning club for girls aged 7–16 that supports interest in science, technology, trades, engineering, and mathematics (STEM). Chapters meet monthly to do fun hands-on experiments and activities. Usually, these events occur at the workplaces of our STEM experts but in response to the pandemic we’ve moved our meetings online and adapted our activities. There are loads of cool things to try at home with CAGIS Virtual, including app development, making your own ice cream, and even extracting DNA!
Here are three tried, true, and kid-approved activities you can explore with your children to inspire some scientific thinking. These experiments are simple, but the concepts are big!
Incredible Ice Melt
When you take a piece of ice out of the freezer and place it on your kitchen counter, it melts, of course. The warmer the temperature, the faster the melt will occur. But did you also know that ice melts under pressure, even in cold temperatures?
You can do a simple experiment to test this out. Take an ice cube and put it on a plate. With a pair of scissors, cut the ends off a cotton swab. Use the stick to press against the ice cube. With some pressure, it will take only a few seconds for the stick to start to sink into the ice. As soon as you release the pressure, the ice refreezes, and you may find you can lift the cube up by pulling on the stick.
You’ll also have observed this phenomenon if you’ve ever gone ice skating. When you place your skate on the ice, the blade (and your weight behind it) exert pressure on the ice. This causes the top of the ice to melt — just while the blade is in contact — allowing your skate to glide across the slippery surface!
Exploring Surface Tension
A super simple experiment with pepper helps to demonstrate the way a small amount of soap affects the surface tension of water.
Fill a bowl with about an inch of water. Grind some pepper (or sprinkle pre-ground pepper) over the top of the bowl. Observe how the pepper floats on the surface of the water.
Now dip a toothpick into some dish soap. You only want a tiny amount on the toothpick. Touch the toothpick to the water’s surface, right in the centre. You’ll notice the pepper suddenly darts to the edges of the bowl or sinks to the bottom. What’s happened?
The pepper flakes can’t dissolve in water. They float because water molecules tend to stick together. The effect of this is that the top layer of water molecules act like a thin elastic sheet — something we call surface tension. Soap breaks down that surface tension. This is one of the reasons we use soap for cleaning.
To do this experiment, you’ll need two eggs in their shells — one raw, and one hard-boiled. They look exactly the same, but with a little science knowledge, you’ll be able to tell which is which, without cracking them!
On a smooth hard surface, give each egg a spin. Observe how they behave. You’ll notice that one egg spins smoothly, while the other one wobbles.
The secret to telling the eggs apart is understanding the principle of inertia. Inertia is the tendency of objects to resist a change in motion. The inside of the hard-boiled egg is firm, so everything moves together, and it spins smoothly. But the raw egg has fluid in it, which resists the spinning motion applied to the shell, and causes the egg to wobble.
Follow CAGIS for more STEM activities!
Membership in CAGIS Virtual costs $200 per year (and $50 for each additional sibling). This includes invitations to 24–28 virtual events per year. Sessions run most Saturdays at 11 a.m. EST (ages 7–12) and 1 p.m. EST (ages 11–16). Our one-hour events include a hands-on activity and time for questions, led by a STEM expert and a certified teacher.