IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: dan.kl on April 27, 2010, 10:15:37 pm

Title: photoelectric effect
Post by: dan.kl on April 27, 2010, 10:15:37 pm

im so confused about this so id really appreciate it if someone can help me :)

okay so i get the general idea of it - electromagnetic radiation of a certain frequency has to be shone on the metal (usually uv light), and photons interact with the metal releasing electrons.
i get all that stuff
but how does this give evidence for the particulate nature of light?
like why cant a wave do this?

and also i get about the wave-particle duality, that particles exhibit wave like properties and vice versa. but if the photoelectric effect is evidence that light is a particle, then how can E=hf where f is the frequency? cause frequency is concerned with waves. so if thats the case then surely it gives evidence that light is a wave!? :S

someone please tell meeeeee :)

Title: Re: photoelectric effect
Post by: ~ A.F ~ on April 27, 2010, 10:23:09 pm

http://www.s-cool.co.uk/alevel/physics.html

the ultimate site for this topic :)

Title: Re: photoelectric effect
Post by: 7ooD on April 27, 2010, 11:14:09 pm

Is it a wave or is it a particle??!!

The answer is - it is both! You have to treat it like a wave to explain what happens to it as it travels (propagates) and treat it like a particle to explain what happens when it arrives (impinges) at a surface.

:P

thx af