# Work function and KE

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#### inaccensa

##### Full Member
15+ Year Member
Energy of photon = KE + work function

If we shine a light whose frequency will only yield enuf energy to satisfy the work function, what exactly occurs at that instant? A photon is ejected ( which is a fact), but it doesn't jump to a higher energy level?

This is the photoelectric effect, right?

if E of light = work function, then nothing happens. The work function is the amount of energy light must overcome to eject an electron. It is dependent on the material.

This is the photoelectric effect, right?

if E of light = work function, then nothing happens. The work function is the amount of energy light must overcome to eject an electron. It is dependent on the material.

I'm saying that if the work function were 1ev and the frequency that was shone yielded 1ev, will the photon eject?

Secondly, if the energy were lets say 1.1ev, then I know it will be ejected and the photon will carry an energy of .1ev, but what happens when its only 1ev

The photon would still be ejected. It just won't have any KE once it's dissociated.

Energy of photon = KE + work function

If we shine a light whose frequency will only yield enuf energy to satisfy the work function, what exactly occurs at that instant? A photon is ejected ( which is a fact), but it doesn't jump to a higher energy level?

That's just like asking, what happens when you exert 1N of force on a block that has weight x coefficient of static friction = 1N. MCAT always avoids this problem by asking "What is the minimum amount of force/energy needed to..."