Clear or Opaque Problem: Why are some materials clear and others opaque? Research the Problem: Sometimes being clear is defined as a quality or purity. Other times, we need to make a substance clear such as glass or varnish. Knowing why and in what condition the material s are clear in can help us achieve the ability of converting opaque materials to clear materials or vice versa if needed. We all have seen glasses, plastic, soap, shampoo, all kinds of food, in clear and not clear conditions. Now we need to find out how being clear or opaque is an optical property of a substance. Hypothesis: In order to make an opaque substance clear, you must make it to one piece of crystal or to totally take away all crystals. To make a clear substance opaque, you must crush and make tat substance into powder, which will take away the clarity. Materials Used: Experiment: We start out the experiment by getting a few clear samples and attempt to make them opaque. For our first test, you will need either salt or sugar crystals. Take one grain of either the salt or sugar, and look at it. As you can see, it is clear and that you can see right through it. Now, take a spoon full of salt or sugar and put it on the same surface. As you can see, it is opaque this time and is not clear, yet it is the same clear grains of crystal. This shows that crystals are only clear if they are in one piece. That means that if you break up that one piece into twenty pieces piled up on top of each other, they will no longer be clear. In the next experiment, take a clear crystal and crush it fully. When you are done crushing it, you will notice that it is a white unclear powder. Even though every single piece of this powder under a microscope is clear, the powder that is a group of clear components is not clear. Next, dissolve the white powder in water. The crystals become clear again. It stays clear until the water evaporates and it becomes crystal again. For our final and last experiment, you will need an ice cube. Take the ice cube and look at it. It is clear for the most part. Now crush the ice and you will notice that it is no longer clear but is opaque. Analyze Datat: Sources: