# De Broglie hypothesis

1. May 16, 2005

### zcapa14

:grumpy: some help with this past exam question would be appriciated....

"Calculate the value of the kinetic energy in eV at which the de Broglie wavelength of a photon is comparable with the size of an atom (~10^-10 m)"

Thanks...

2. May 16, 2005

### Staff: Mentor

The energy of a photon is given by $E = h \nu$.

3. May 17, 2005

We use $E = hf$ in most UK schools, Doc Al, not $E = h \nu$
(I don't know why we use different symbols for the same thing... it can cause confusion!)

4. May 17, 2005

### dextercioby

Please,post future problems in the Homework Section of this forum.

Daniel.

5. May 17, 2005

### Kruger

I hate the second form of expressing the energy of a photon (E=hv). Because the "v" can't really be differed from the velocity, ... (the signs are almost the same).

6. May 17, 2005

### Staff: Mentor

I'll have to keep that in mind.