Science At Home - Self Crushing Can

Sometimes you need to crush an empty can, but it’s kind of boring just to stomp on it! Instead, put science to work for you and let the can crush itself!

What You Need

• Empty pop can

• Tongs

• Heat source (a candle will do)

• Pan or shallow tub of cold water

What you do

1. Fill a shallow pan or tub with water. There should be enough water to go part way up the pop can.

2. Add a small amount of water to the pop can.

3. Using the tongs, hold the pop can over the heat source, open side up. Hold it there, moving the pop can slowly from side to side until you see steam appear. You could also place the pop can on a stove burner or barbecue grill if you prefer.

4. Carefully and securely grasp the pop can with tongs and quickly invert it into the water. The opening of the pop or soda can should be submerged in the water.

5. Be prepared for the implosion! The can just crushed itself!

Explanation

By adding heat to the pop can with a bit of water, the water turns from a liquid into a gas. This gas is water vapor which pushes air inside the pop can out. When the can is turned over into the pan of water, the water creates an airtight seal.

The cold water cools the air inside the can and the pressure rapidly changes. The air outside the pop can can’t get in because the water in the dish is creates an airtight seal on the can.

As a result, the air pressure outside of the can is higher than the air inside the can. The can isn’t strong enough to resist - and the can collapses under the presser. This is called an implosion: something collapsing or squeezing into itself.

When you lift the crushed pop can up, you might notice it is filled with water. This water is pushed into the pop can as the pressure equalizes.

Taking it further

The physics of this demonstration are similar to the Water Lifting Candle demonstration. Why does the pop can implode, while the glass or jar do not?

Things to note

Be sure to have water in the pop can. The water is needed to create water vapor.

You may want to have oven mitts to hold the pop can.

Any time you are using a heat source, take extra safety measures.

Always wear safety glasses.

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Science At Home - Color Changing Milk

Color Changing Milk Demo

Explore bipolar molecules - those that are simultaneously hydrophobic AND hydrophilic!

What You Need

• Shallow dish

• Food coloring

• Milk

• Cotton Swabs

What You Do

1. Pour enough milk in the dish to completely cover the bottom. Let the milk settle.

2. Add a small amount of each of the colors of food coloring. Keep the drops close together near the centre of the dish.

3. Next, pick up your cotton swab. Touch the tip of the swab into the centre of the milk - it’s important that you don’t stir the milk. What happens?

4. Now, place a drop of dish soap on the other end of the cotton swab. Dip the soapy end of the cotton swab in the middle of the dish and hold it there for a few seconds. What’s happening now?

5. Add more soap to the cotton swab and try again. Experiment by moving the cotton swab to different places in the dish.

What makes the food coloring in the milk move?

Explanation

Dish soap is bipolar - that is, a soap molecule has a polar end which is hydrophilic (water loving) and a non-polar end which is hydrophobic (water fearing). The hydrophilic end of the soap molecule dissolves in water while it’s hydrophobic end attaches to fat molecules in the milk.

Milk is made mostly of water, which makes it easy for the hydrophilic end of the soap molecule to dissolve, but it also contains many other things such as vitamins and minerals. Milk also contains fat. The hydrophobic end of the soap molecules want to attach to the fat molecules.

As the soap molecules and the fat molecules interact, they move around in a little soap dance. While this dance, or gymnastic routine, is happening, the food coloring is moved all around the dish, giving us an easy way to observe the activity.

Science At Home - Water Lifting Candle

Hey Science Fans!

Here’s another great activity that you can do at home to amaze your friends and family (and explore learning with your kids!)

Instructions

WATER LIFTING CANDLE DEMONSTRATION

Here’s what you’ll need:

• Pan, plate, or flat-bottomed dish

• Water (add food coloring to make the effect even more visible)

• Tea light or small candle

• Matches or lighter

• Tall glass cylinder, drinking glass, vase, etc

Warning! This activity uses fire. Make sure there is an adult present to help!

What you do

1. Pour some water (colored water is best) into a shallow dish or pan

2. Place a candle into the dish

3. Carefully light the candle

4. Place the glass upside down over the candle.

5. Watch as the candle goes out. What happens to the water?

What’s happening?

The “Fire Triangle” outlines the three things required for fire to be present: oxygen, fuel, and heat. When one of those items is missing, a fire can not start. If one of those resources is used up, the fire will go out. By placing the glass over the candle, you limit the amount of oxygen available to the fire. When the oxygen in the glass is used up, the candle goes out.

The flame of the candle creates heat which warms the air inside the glass. As the air inside the glass warms, it expands - you probably noticed some air bubble leaking out from under the glass while the candle was burning. When the candle goes out, the air in the glass cools. As the air cools, it contracts. This creates an area of low pressure inside the glass - a partial vacuum. The air pressure outside the glass remains constant, pushing down on the water in the dish.

The area of high pressure (atmospheric pressure) pushes down on the liquid in the dish, forcing it to go into an area of lower pressure (the space inside the glass). When that happens, the water level inside the glass will rise higher than the water level outside the glass. When the air pressure inside the glass and outside the glass are equal, the water level stops rising.

Experiment!

Does the size or shape of the glass make a difference?

Does the temperature of the glass have an effect on the outcome?

Does the amount of water in the dish have an effect on the outcome?

Science At Home - Polymers

Hey Science Fans!

Here’s a couple of great activities that you can do at home to amaze your friends and family (and explore learning with your kids!)

Instructions

ZIPLOC BAG DEMONSTRATION

Here’s what you’ll need:

• Ziploc Bag

• Water

• 2 Sharp Pencils

Fill the Ziploc bag with water and seal it. Poke the pencils through the bag, being careful not to tear the bag.

What’s happening?

The polymers in the bag (in this case polyethylene) are flexible enough to allow the pencils to pass in between the molecules. Because they are slightly stretchy, they fill any gaps between the pencil and the bag, keeping leaks to a minimum.

Experiment!

What happens if you use something really thin, or really thick instead of a pencil?

Further Reading:

https://www.stevespanglerscience.com/lab/experiments/leak-proof-bag/

BALLOON DEMONSTRATION

Here’s what you’ll need:

• Latex Balloon

• Toothpick

• Deep breaths

Inflate the balloon about halfway so that it has a nice round shape, but isn’t completely full. Tie it off so that it doesn’t leak. Insert the toothpick in either the base of the balloon, or near the top of the balloon.

What’s happening?

The polymers in the balloon (in this case latex), are very stretchy AND thicker near the base and top of the balloon. Because the balloon isn’t fully inflated and the balloon is thicker near these points, the polymers can still stretch to fill the space created by the toothpick. The balloon pops if you stick it on the side because the balloon is thinner there and the polymers are stretched further apart.

Experiment!

Using a wooden skewer, try to pierce both the bottom AND top of the balloon at the same time.

How big can you inflate the balloon before it pops when you try the demo?

Further reading:

https://www.stevespanglerscience.com/lab/experiments/skewer-through-balloon/

Atom + Geek Science Shop Home Delivery - Tin Can Cable Car

Are you feeling stuck at home? Looking for fun things for your kids to do?

The Atom + Geek Science Shop is now offering FREE HOME DELIVERY* in Regina!!

*Free home delivery is next business day Monday - Friday.

Introducing the Tin Can Cable Car: This kit introduces the basics of mechanical engineering and renewable materials in a fun, hands-on way!

Explore the exciting worlds of mechanical engineering and green science with the 4M Green Science Tin Can Cable Car Kit. Assemble the cable car using a recycled soda can, then string the cable between two points and watch the car make its ascent.

This kit contains all the parts necessary to assemble one cable car. Requires one soda can, a screwdriver, and two AAA batteries. Detailed instructions included. Recommended for ages 8 and up.

Need help with assembly? Check out this video and follow along!

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