CHEMISTRY COMMUNITY

What is the work function? Most of the time it's given in a problem, but I don't understand what is the meaning behind it.

The work function is the amount of energy required to expel a single electron from the metal

It is the minimum threshold needed to eject an electron from the metal.

The book says work function which is also considered threshold energy. Think of it as the limit the incoming photon light has to exceed in order to release the energy as it hits the metal.

I hope this helps. Correct me in places where I might be wrong.

In order to find the work function or the threshold energy, you either have to set it equal to the energy per photon if given the lowest frequency or subtract the Ek of the electron from the energy per photon. Often it asks for the threshold energy to be in kJ/mol, however, so then you would have to convert the value.

Work function is the minimum quantity of energy that is required to remove an electron from a metal.

It is given by the equation energy supplied by a photon - kinetic energy of the ejected electron, or hv - (1/2)mv^2

Its just the energy required to remove an electron

An important point is that it is the amt. of energy required to remove an electron from an atom such that it comes off with zero kinetic energy. There's no energy left over to move the electron away from the atom, only enough to detach it.

Is there an actual equation for the work function, or will it always be given to you?

The equation to solve for the work function is E(Photon)=Work Function(Threshold Energy) + E(Kinetic)

i was confused about this too, so it's just that equation?

Work function is just a synonym for threshold energy. It is not an equation, it is the minimum energy needed for an electron to be ejected from a metal. The value is usually given.

A work function is the minimum energy needed to remove an electron from a solid surface to a point in the vacuum immediately outside the solid surface.

The Work function (threshold energy) is the energy needed to expel one electron from metal in a vacuum.