(a) State Heisenberg’s uncertainty principle
(b) mention two phenomena that can only be explained in terms of the particulate nature of light
Explanation
(a) Heisenberg's uncertainty principle states that there is always an uncertainty in any attempt to measure the position and momentum of a particle simultaneously
(b) Phenomena explained in terms of particle nature of light are:
- photoelectricity,
- black body radiation,
- compton effect