Question :

$-$ Note down the colors you observed and the sequence they show on the white board.

$-$ Draw the path of the light.

$-$ Explain why there are so many colors and why they show in such a sequence.

$-$ Compare the indexs of refraction of different color light.

$-$ Compare the wave length of different color light.

$3.$ Put the other prism besides the first prism. Move the white board to get the shadow.

Question :

$-$ Explain why the colors disappear.

$-$ Draw the path of the light.

$4.$ Put the equipment in order and clean the desk.