You may hear adults talk about how many inches of snow fell during a snowstorm. Do you think that's the same as how many inches of water fell? Try this experiment and find out! (If you don't have snow where you live, you can still have fun making your own crystal snowflakes!)
Snow is made when water freezes in the form of ice crystals that we call snowflakes. The pointed star-like shape of a snowflake causes its points to stick out far from its body, allowing the snowflake to take up a lot of room. (If you stick your arms straight out from your body, something similar would happen with you! Your arms cause your body to take up more space and you may find yourself bumping into walls or having a hard time making your way down a hallway with your arms sticking straight out.) When lots of snowflakes pile up, their points keep them from getting very close together, creating empty space in between the snowflakes. When the snow melts into water, the snowflakes no longer have their points, and the space between them disappears. (If you put your arms down next to your body, you are no longer taking up so much space and can get much closer to other people and things.) So the melted snow takes up less space as water than it did as snowflakes.
Hailstones are chunks or balls of ice that sometimes fall during thunderstorms. To find how this happens, read our Teacher Tidbit section on hail. Have you ever heard of golf-ball-sized hail? Or maybe you have heard of pea-sized hail. Where do people get these strange names for hail? Try this experiment to get an idea of how hail sometimes gets weird names.
Gather as many of the following objects as possible:
For older kids:
When a hailstorm hits an area, it's hard not to notice the pieces of ice suddenly falling from the sky. Depending on the storm, these pieces of ice can range in size from very small to very large. Knowing the size of the hail is important because it gives us an idea of how strong the storm is that made the hail. In general, the larger the hail, the stronger the storm. The common objects that you used in the activity represent common hailstone sizes.
If you have ever tried to guess the size of hailstones in inches, you may have found that hard to do - most people do. Getting an accurate size of the hailstones is tricky unless you have a ruler handy to measure whenever a storm happens, plus hail usually melts quickly since it comes with summer storms and warm temperatures. To make it easier, we usually estimate the size of hailstones by comparing them to common round objects, like the ones listed above. The next time you experience a hailstorm, go outside after the hail has stopped falling and see if you can find any hailstones left on the ground. Then think of as many objects as you can that the hail is similar in size to.