Elmer learns the following facts about the sky in science class: the sky is blue because of the way the air scatters light from the sun. the colors at sunset are partly due to the fact that the sun is shining through a much thicker layer of air. adding a small amount of milk to water can cause the water to scatter light. elmer decides to use a model to see if he can recreate some of the colors of a sunset. what should he use in his model?