Try this at home

Maintaining Equilibrium

Whipping out a science experiment in the middle of a rip-roaring party might not be the best way to make new friends, but no one said you can’t get your nerd on during a boring Sunday evening when you’re lucky enough to have completed all your assignments. Even if you’re not finished all that homework, what better way to procrastinate than having fun with science in the comforts of your own home; at least you might learn something other than the latest scandal rocking Wisteria Lane.

Alka-Seltzer® rockets

What you’ll need:

Alka-Seltzer® tablets Water Film canister (those little plastic cases used to hold

How you’ll pull it off:

Fill the canister half-way with water. Add half an Alka-Seltzer® tablet and snap the lid in place. Get out of the way and prepare to be dazzled. Note that this is an outdoor activity.

Where’s the science?

Chemistry propels your rocket. The tablets contain citric acid and baking soda (sodium bicarbonate) that when dissolved in water react to produce carbon dioxide gas. Gas produced in a confined volume leads to high pressure, which eventually blows your cap off, propelling your rocket to the stars – or at least several metres in the air. For the engineers out there, try altering the shape of your canister with some carefully folded Bristol board to enhance your rocket’s flight.

Swirling milk

What you’ll need:

Homogenized milk (fat is where it’s at) Food colouring Dish soap Toothpick Small container (shallow bowl, cup, etc.)

How you’ll pull it off:

Pour some homogenized milk into your container. Wait for the milk to settle then add a couple of drops of food colouring. The colour should stay in a circular shape on the surface of the milk. Dip one end of the toothpick in some dish soap then place the soapy toothpick in the center of one of the food colouring drops. Enjoy the magic of psychedelic swirling colours.

Where’s the science?

There’s really a lot going on in this simple demonstration. Milk is actually a colloidal mixture, which means it’s made up of tiny fat droplets dispersed in a water-based liquid. The food colouring likes water, so it doesn’t like to spread throughout the milk, but when the soap is added all bets are off. The active ingredients in soap are special molecules called surfactants, which help oil and water get along; kind of like a mother who threatens Johnny with a spanking if he’s not nice to his sister. The surfactants lower the milk’s surface tension and send the fat droplets speeding through the fluid, swirling the food colouring in the process. Who would have thought swirling milk was so complicated?

Magic mud

What you’ll need:

Five Tbsp. Cornstarch Three Tbsp. Water Bowl

How you’ll pull it off:

Place the cornstarch in the bowl, add water, and mix until smooth. Now, roll up your sleeves and prepare to get your hands dirty in the name of science. Try slapping the mixture with a firm hand; it should feel solid. Try gingerly placing your hand in the mixture and feel the ooze of the liquid. Not quite as flashy as a rocket, but fun nonetheless. Sound like magic? It ain’t.

Where’s the science?

This is another example of a colloidal mixture. The cornstarch doesn’t like water enough to dissolve, so it’s dispersed as tiny particles throughout the liquid. This concoction, typically used to thicken sauces, is known as a dilatant material, which means its viscosity – how readily it flows – changes depending on how fast a force is applied. Next time you need to thicken the gravy, mix up some cornstarch and water, fling a little at the wall and take notes.

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