 Observations are an important skill of a scientist. What I want you to do is to set up an experiment and observe it for a week. First, take a test tube and put about an inch of copper sulfate in the bottom of the test tube. And then take a piece of filter paper. If you don't have filter paper, something like a coffee filter will work. And put that just down into the test tube to sort of make a little barrier. On top of your filter paper, pour in about an equal amount of sodium chloride. So just table salt. And then add another piece of filter paper. When you have your filter paper in place, now take an iron nail and drop the nail in the test tube. Fill the entire test tube almost to the top with water. And put a stopper to keep dust and other debris from falling into it. So I want you to write down, draw a picture in your notebook of what you observe. And each day you come to class for the next week, I want you to look at this test tube and draw the changes that you see occurring. And save that test tube because at the end of the semester, we're going to take that test tube apart and see what's on the inside.