Question

predict and write why other colours cannot be observed at the same time when one colour is emitted

Answer 1

Here are the seven colours of the spectrum listed in order of their frequency, from the lowest frequency (fewest waves per second) to the highest frequency (most waves per second):

red

orange

yellow

green

blue

indigo

violet

This mnemonic is one way to remember the order: ‘Richard Of York Gave Battle In Vain’.

Coloured light