The first diagram shows a ray of yellow light as it approaches and enters a glass prism. The yellow light ray is then replaced by a white light ray, which separates into red, orange, yellow, green, blue, indigo and violet.

1. aName the process that leads to the yellow light ray changing direction as it enters the glass prism. [1]
2. bDescribe the path of the yellow light ray as it leaves the glass prism (draw it on paper). [1]
3. cName the phenomenon where the white light ray is separated into several colours by a triangular prism. [1]
4. dWhich natural occurrence is a result of white light separating like this? [1]

You'll mark your own answer against the marking guide when you hand it in.