Review of image formed by a plane mirror. Definition of terms regarding image: upright, inverted, virtual and real. Show examples of concave and convex mirrors, and using a candle object, view the image formed by each one and describe it in terms of size, position, and ray formation. A glass block was used to show refraction of light as the laser beam passed from one medium into another. The ray was sketched on a white paper, the normal shown, the incident ray shown, and the refracted ray shown. One of the rules of refraction was derived from the direction of refraction in relation to the normal ray and the difference in media density at the surface between the 2 media.