The next time it rains, ask your child what happens to the puddles. Where do they go? How long does it take them to disappear? Why do they disappear? He or she may not know anything about the water cycle yet, but that's okay. It'll get your child thinking. Sometimes, the questions can be more important than the answers.
Science can be an intimidating subject. That's why the best teachers start out a new topic by somehow linking it with the real world. If they build up curiosity, the students will want to seek out the answers. Their focus will no longer be upon how hard it is, and the experiments they do will have value and meaning.
So, today I'd like to share a simple experiment that you can do with your child to help him or her learn about evaporation. You should only start this project if your child seemed interested in the puddle conversation, and only if he or she wants to.
When you and your child have five free minutes, remind your child about the puddle conversation, and ask him or her what you can use to make two equal amounts of water. If he shows you two glasses of the same size, that's great. You can then follow up by asking if there's something else you can use to keep track of how much water "disappears." Take out two measuring cups and have your child fill them each up to the one cup line.
Ask him or her why you need two cups of water, rather than just one. Without giving away the answer, ask about whether or not two puddles of the same size would disappear in the same amount of time. What factors might affect the rate of "disappearance"? Keep asking questions that will guide them to the different effects that the sun and the shade would have upon a puddle. Then, ask where you should place each cup. One should be in the shade, and the other in the sun.
Ask your child to predict how long each cup will take to disappear (how many days). What is this process of "disappearing" called? Notice that the word, vapor, is in evaporation. You can explain that the water doesn't disappear, but instead turns into a gas, or water vapor. The same thing happens when you see steam coming off of a pot of boiling water. The hotter the water becomes, the more quickly it evaporates. So, water never disappears. That's why we call it the water cycle.
Be sure to leave the two cups of water uncovered in places where they won't be disturbed. You and your child should look at them every day to see how much of the water is gone. If you want to get fancy, then make a little chart to record the measurements, and the corresponding dates and times, when you check your water samples. Otherwise, just check to see which cup is evaporating the fastest. It should be fun for your child, not work. So if your child doesn't want to document the information, do not force her to. That choice is a luxury you have, that paid teachers do not. Like I always say, follow your child's lead.
Okay, it will take you days to complete this experiment. Have fun with it. Evaporation is only one part of the water cycle. In the meantime, keep talking about water. You may also refer back to A World of Water, Part 1. Feel free to share your experiences!
Tomorrow, we'll talk about condensation. I also have some wonderful picture books and a song to help bring it all together. Have a wonderful day!
You can find the link to part 3 here.
