1. Warm-Up: Luminescent or Incandescent? A)Fire B)Fluorescent light bulbs C)Toaster element D)A glow stick E)A firefly F)Glow in the dark watch G)A computer monitor H)The Sun

2. Ray Model of Light LG: I can explain how rays of light behave when they contact different objects Why can you see your reflection in a spoon, but not in a piece of concrete? Why can you see through some glass but not wood?

3. The Ray Model of Light Light is represented as straight lines with arrows to show the direction that light travels; they show us the path that light takes after it leaves a source. This is called a ray. Example:

4. Light Rays Rays of light will travel in a straight line until they make contact with something Some objects allow the light to pass through and others cause the light to bounce back What kinds of objects do you think light rays can pass through?

5. Transparent – most light passes through, very little absorbed or reflected Translucent – Some light passes through, but light rays scatter and change direction (can see through but image is not clear) Opaque – objects reflect and absorb all light; none passes through

6. Opaque Objects and Reflection If the surface of an object is smooth, light rays are reflected parallel to one another and the image looks the same as the object If the surface is rough, the light rays will be scattered and no recognizable image can be seen