State whether light slows down or speeds up in the following cases:

(a) Light going from air to glass.

(b) Light going from glass to water.

(c) Light going from water to air.

What are primary colours? Name the three primary colours.

Fill in the blanks with the appropriate colour:

(a) Blue + ……………. = Cyan

(b) Red + Blue + ………………… = White

(c) Red + Blue = ………………..

(d) Green + Red = ……………………

The leaves appear green when seen in white light. Give a reason.