One way that crystals form is from chemicals dissolved in water. If the water gets cooler, dissolves other chemicals, or evaporates, some of the dissolved chemicals can be deposited as crystals. Often, growing crystals can be a fairly long, involved process, but with this activity, we will grow some nice crystals quickly and easily.
This experiment is another old classic which is still a lot of fun. Now that I think of it, it seems that most of the science tricks I did as a kid have become OLD classics, but this was already an old classic even way back then.
I have been doing some house cleaning. In cleaning the counters, I noticed a coffee spill that had dried. It had formed a dark ring, with almost no coffee stain in the center. This reminded me of an article that I have read on the science behind coffee rings, giving me the idea for this experiment.
This experiment is the result of my forgetfulness. I took a tray of ice cubes out of the freezer, used half the cubes and then forgot to put the tray back in the freezer. When I remembered, the cubes were half melted. Only the centers of the cubes were left, and that ice was very cloudy.
I love it when teachers ask questions! I alway enjoy a good science question because they make me really think about the subject to be sure I give the right answer, but when a teacher asks a question, I feel obligated to give an answer (if I can) that will let them explain the subject to their students. Recently, I have been talking with a teacher friend, about chemical and physical changes, and the more we talked, the more I thought the rest of you might find this useful.
The word rock means different things to different people. As with many words, its scientific meaning is different from many of the meanings used in everyday language, so lets start with a short video on the scientific definition of a rock.