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After this winter, it's safe to say we all know what frozen looks like. But what about a frozen bubble? Find out in this week's Saturday Science experiment!
Materials
- Liquid Soap
- Water
- Large bucket or dish
- Straw
- Plate
- Freezer
Process
- Prepare your "bubble juice." Mix up water and baby shampoo, or any liquid soap, in a large bucket or dish.
TIP: To make soapy water that will produce nice, solid bubbles, combine: 125 ml liquid dish soap, 125 ml corn syrup, 750 ml hot water. Mix and let cool.
- Dip your straw in the "bubble juice." Get your straw, or your choice of "bubble wand," and dip it in the "bubble juice." There should be a film of the solution at the end of the straw. Carefully move the straw near your plate.
- Blow your bubble. Blow a bubble of any size, just make sure it can fit on the plate. Don't blow it directly onto the plate; blow it right over the plate.
- Put your bubble on a plate. Carefully place your bubble on a plate. Your bubbles may pop several times before you can finally put one onto a plate.
- Freeze your bubble. Put the dish very gently inside a freezer. Wait for about 30 minutes to an hour, checking on your bubble every 15 to 20 minutes.
- Take out the bubble. When your bubble is frozen, take out the plate very gingerly, making sure it does not crack. It will last for about 10 minutes, more or less.
Results
Some bubbles will freeze instantly, while others will freeze slowly. If you are careful, you can sometimes hold a bubble in your hands without bursting it. Why are the physical properties of frozen bubbles so different? A bubble is formed by a layer of water molecules trapped between two fine layers of soap molecules. When it is very cold, and the bubble wand is waved very slowly, the water layer freezes before the bubble can burst.
If you make a bubble by blowing into the wand, the bubble takes more time to set. The air in the bubble has been warmed by your lungs, and when this warm air comes into contact with cold air it contracts, and the surface of the bubble sets slowly. In both cases, the layers of soap freeze, making the walls of the bubble more solid. After a few seconds or a few minutes, the air captured inside the bubble disperses to the exterior, like a balloon deflating, and the wall of ice collapses under its own weight. Look at the frozen soap wall of a bubble — it looks like a broken eggshell.
