(a(i))[1]
Draw the normal where the ray of red light enters the glass block.
(a(ii))[2]
On Fig. 6.1, label every ray with words chosen from the list: diffracted, diffused, dispersed, incident, reflected, refracted.
(b)[2]
For each lens, draw the route taken by the two rays as they go through the lens and re-enter the air.
(c)[2]
State the seven colours of visible light. Give the colours ordered by frequency.