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## Homework Statement

Hi there. I have two questions and in both I believe that no photoelectrons will be emitted from the surface.

Question 1

A metal with a work function of 9 x 10^-19 J is irradiated with UV radiation of wavelength 180 mm. Will photoelectrons be emitted from the surface?

## Homework Equations

## The Attempt at a Solution

E = hf

f = c/λ

E = hc/λ

E = 6.63 x 10^-34 x 1.67 x 10^9

= 1.10 x 10^-24 J

The energy required to release the an electron from the metal is E0 = 9 x 10^-19

Therefore, the energy contained in the light, is insufficient to overcome the forces holding the electron to the surface of the metal.

The second question is that the same metal is used but this time irradiated by 550 nm

I come up with the following - which again indicates that nothing is released.

E = hf

f = c/λ

E = hc/λ

E = 6.63 x 10^-34 x 5.45 x 10^14

= 3.61 x 10^-19 J

Can someone please check, as the next question asks

Determine the maximum kinetic energy and velocity of any photoelectrons emitted in the above questions. But my calcs indicate that no photoelectrons are emitted. (The electrons rest mass is 9.1 x 10-31 kg.).

Cheers and thanks in advance