One of the best ways to teach children about science is by conducting some fascinating experiences. Dry ice can be one of those elements. It is a substance that can be used for making science fair projects. Dry ice is nothing but carbon dioxide in its solid form.
Carbon dioxide is a gas which is an important component of the Earth's atmosphere. When it is frozen above -56.3º C and pressure below 5.13 atm, carbon dioxide gas converts into its solid state without an intervening liquid state. This solid carbon dioxide is what we need. This is used extensively in the meat packaging industry and in food preservation.
Before we learn about some easy experiments, it is important that you know how to handle it. Being extremely cold, it can cause damage to the skin in the form of burns and frostbite. So, always wear insulated gloves while handling it.
While transporting, make sure that the car windows are open, so that there is adequate ventilation. And lastly, do not let small kids handle it without adult supervision.
For this experiment, you will need dry ice pellets, soap, water, and a glass bowl. First wear a pair of insulated hand gloves and place a pellet in the bottom of the glass bowl. Allow carbon dioxide gas to accumulate in the glass bowl from it. In another bowl or container, dissolve a bit of soap in water to make a soapy solution.
Blow some bubbles through a wire loop into the glass bowl containing the ice. You will notice that the bubbles will hover in the air in between the pellet and the carbon dioxide gas.
The bubbles which comes directly in contact with the pellet will freeze into transparent solid bubbles. You can then touch and hold these frozen bubbles in your hand. After some time, the frozen bubbles will thaw and then pop.
Carve a mouth, eyes, and nose on the pumpkin. Fill water inside the tall glass or can and place it inside the pumpkin. Make sure that the glass is not toppled inside. Now, drop a few pellets into the water and close the lid of the pumpkin. After sometime, you will see a thick fog emanating from the eyes, nose, and mouth of the jack-o-lantern.
For best results, the glass or can of water that you place inside the pumpkin should be taller than the cut-out for the eyes. Since carbon dioxide gas is heavier than air, it tends to settle at the bottom of the container, which in this case is the pumpkin; more fog will come out of the carved mouth of the jack-o-lantern.
A Howling Spoon
Ever heard a spoon squeal and shriek? Well, in this next fun trick, kids will hear just that. For this experiment, you need a regular metal tablespoon and a pellet. Dry the metal tablespoon and make sure that it is free of moisture. Place a pellet on the metal spoon and press it firmly to the surface of the spoon.
As the heat from the spoon transforms into vapor, it puts pressure on the spoon, which makes the spoon make a small movement. This movement causes a squeaking noise, making it seem like the spoon is shrieking.
These experiments for kids are a lot of fun, and kids gain a lot of information about carbon dioxide and its properties. Whenever you conduct these, make sure that children are safe. Also make sure that the place where you conduct such experiments is preferably outdoors or is well-ventilated.