General Q about photoelectric effect terms [ENDORSED]

[Lindsay H 2B]

When a question asks "how much energy is required to remove an electron from a metal surface?" is it asking us to find the threshold energy or the energy of the photon?

[Chris Pleman 3E]

Threshold energy, unless specified otherwise.

[Jessica Beroukhim 3K]

To build on that, the energy of the photon is how much energy goes into system, but it can be more or less (or the same) as thee threshold energy. It's unrelated. But if you're given the kinetic energy or velocity of the electron afterwards, you can use that and the threshold energy to find the energy of the photon.