Threshold Energy

[MaryBanh_2K]

What happens if the energy of light matches the threshold energy level? What would happen to the electron(s) on the metal surface?

[BNgo_2L]

If the energy of the light equals the wave function (threshold), electrons will still be emitted, but there wouldn't be any excess energy (kinetic energy).

[Gabriella Bates 2L]

If the energy of the light matches the threshold energy, then electrons will be emitted from the surface. If the energy of light is greater than the threshold energy, then the electrons emitted will have increasing kinetic energy.

[Kimme Chun 1I]

The electrons will be emitted but KE will equal 0.

[Eesha Sohail 1D]

Can something still be emitted with zero KE? It seems as though that would cause it to not move at all, and therefore not break free of the metal surface. However, it's possible I'm ascribing expectations of regular matter to the quantum level where they don't really apply.

[Ashley Fang 2G]

I think that "ejected" just means that the electron is released from the atom. The detector that is used to measure the KE of the ejected electron has a slightly positive charge, thus causing it to move.

[Tiffany Dong_4e]

I'm also confused how an electron is "ejected" with no kinetic energy. Could someone clarify further?

[AlyshaP_2B]

I believe that saying there is 0 KE means that after the electron has been ejected, there is no excess energy leftover that would be considered Kinetic Energy. When the energies match up, all of it is used to eject the electron so there will be 0 KE.