# Photoelectric effect and work functions

1. Jun 2, 2005

### bullroar_86

what can be said about the work functions of two metals when the threshold wavelength in the photelectric effect increases.

I'm having trouble finding and equation to describe this relationship.

ANyone have any ideas?

2. Jun 2, 2005

### Nylex

Well, the work function, $\phi = hf_{0}$, where $f_{0}$ is the threshold frequency. Do you know the relationship between frequency and wavelength?

3. Jun 2, 2005

### Dr.Brain

Threshold wavelength is inversely proportional to the work function of the metal .
Of course the threshold wavelength is decided by the metal itself.

For the critical case the work function is $\phi$ is related to the wavelength as:

$\phi$$= \frac{hc}{ \lamda }$

4. Jun 2, 2005

### Nylex

You spelt lambda wrong, that's why it won't come out.

5. Jun 3, 2005

### ElectroPhysics

If the photon energy exceeds the work function, the excess energy appears as the kinetic energy of the electron.