Why is the photoelectric effect cited as an example of a particle-like nature of photons?
The photon's not physically knocking off the electron, right?
It's supplying energy to break the bond, hence the work function of a metal.
It's like placing a popcorn kernel over a flame. It pops because it's had energy supplied, not because the fire punched it.
Am I missing something?
Best Answer
The energy is delivered to the metal in discrete packets.
If you think of light as a wave, than one may expect that a low-energy colour of light should be able to (eventually) liberate electrons from the metal if you wait long enough (as more and more energy is deposited into the metal). Because electrons are not liberated below a certain energy threshold (color of light which happens to be the work function of the metal), the conclusion is that the energy is given to the metal in discrete packets (particles).