Tired of being trapped inside all day during the winter, but building snowmen or making snow angels is getting to be a little too much of “been there, done that?” Never fear, we have some great science experiments that will make your time outside more enjoyable!
Turn Boiling Water Into Ice In The Blink Of An Eye
During 2014’s Polar Vortex, it became a viral sensation to throw boiling water out into the freezing air and watch the water freeze before it even hits the ground. How is this possible?
First of all, the air needs to be extremely cold and dry in order for this to be successful, around -30 degrees Celsius (-22 degrees Fahrenheit). This alters the density of the air, which doesn’t allow it to hold much moisture. The boiling water, on the other hand, eagerly offers up water vapor. Throwing the water into the air exponentially increases the surface area, allowing more water vapor to escape. The air can’t hold this moisture, so the vapor is quickly cooled and condensed. The water sticks to particles in the air to form the nucleus of a snowflake as it freezes.
Caution: Though the freezing air will cool the water very rapidly, please take extreme caution while performing this experiment. If the wind changes direction or the temperature isn’t as low as it needs to be, this can quickly get very dangerous and cause severe burns. Please do not attempt to throw the water toward someone else.
Blowing bubbles is always a good time, and they get to be even more fun when they are frozen! Head outside to blow your bubble and watch the fractals cover the surface as the bubble freezes. If they freeze in the air, they’ll break as soon as they land. To marvel at your bubbles for even longer, blow them close to the snow, and allow them to freeze on the ground.
You can use pre-made bubble solution or make your own by mixing one part water with four parts soap (dish soap works very well, though shampoo could also be used). If you want to make the bubbles more durable, add in a small amount of glycerin or light corn syrup. Creating tougher bubbles will improve your chances of getting to pick the bubble up and getting a closer look after it is frozen.
This is a fun exercise in exploring the relationship between the volume and temperature of a gas. Inflate a balloon inside your home (which is hopefully considerably warmer than the outdoors) and tie off the end. Take the balloon outside, and watch the balloon slowly deflate as the gas becomes colder. Bringing the balloon back inside and allowing the gas to become re-heated to its original temperature will re-inflate the balloon.
This phenomenon is due to Charles’ Law, which describes the relationship between the volume and temperature of a gas. As the temperature of the gas inside the balloon decreases from the frigid air, the volume also decreases in order to maintain the pressure of the gas. As the volume of the gas shrinks and becomes more dense, it doesn’t put as much pressure on the sides of the balloon, causing it to deflate. Once the balloon is back indoors, the temperature of the gas will increase, which increases the volume of the gas, and then pushes and stretches the balloon. Though the container and pressure of the gas inside never changed, you are able to manipulate the volume by changing the temperature.
To make this activity even more fun for kids, you can draw on the balloon to see how much the picture changes as the balloon deflates. You could also try inflating the balloon outside (though good luck tying it off with cold fingers!) and bringing it inside to see how much bigger it can get before it pops.
Self-Freezing Soda Slushy
This experiment is similar to the video we showed you over the summer, where you could make ice instantly with super-chilled water. This time, we’re making a delicious frozen treat using a bottle of your favorite soda. All flavors should work, even diet.
Start by vigorously shaking a bottle of room temperature soda, but be sure to use one that has not been previously opened. Though shaking up soda is typically frowned upon, it is important to increase the internal pressure of the bottle as much as possible for this. Stick the bottle out in the snow or anywhere it can receive consistent sub-zero temperatures, and wait a couple of hours. The temperature of the snow and size of the bottle will determine how long it takes. The goal is for the soda to be below freezing temperature without actually turning into a solid.
When the bottle is ready, be sure to pick it up very slowly and steadily. Carefully unscrew the lid and pour the soda into a chilled glass. This will create the nucleus that the soda needs to begin the chain reaction of forming ice crystals. As you pour, the soda will turn into a delicious slushy right before your eyes.
There is a bit of finesse in getting this experiment to work, so you might want to start out with smaller bottles, rather than a 2 liter. Allowing the bottles to stay in the snow for too long will cause it to freeze in the bottle, which will not allow it to become a slushy when it gets poured. Jostling the bottle too much after you unscrew the lid is enough to begin the nucleation process, which is also why you need to be careful when you pick the bottle up out of the snow and bring it to your work area. If the slush is staying at the top and not spreading throughout your container, just give it a stir to help the reaction along.
Click here to see a video of this experiment in action.
Ice On A String
This experiment is cool, because it allows you to pick up an ice cube without even touching it! All you need is table salt, string, ice, and a tiny bit of water. The string can be as long as you want it to be, provided it’s long enough to cover one side of the ice and you have enough to hang onto.
Set the ice cube on your work surface and allow it to slightly warm up for a couple of minutes. Lightly moisten the string with the water, and set the moistened section of string over the ice cube, ensuring that they’re making good contact with one another. Then, cover the string with table salt. Wait about 20-30 seconds and then pick up the other end of the string to see the ice cube fully attached! The table salt reduces the melting point of water and helps to slightly melt the already-warming ice. The temperature from the inside of the ice cube refreezes the water, fusing it to the string.