Ionization Energy vs. Threshold energy

[Ann Pham]

Are there any differences between the ionization energy and the threshold energy?

[Alex Nguyen 3I]

I think both are the same (i.e. an electron is removed from the atom). I know ionization energy is with regards to gases, and threshold energy was associated with the photoelectric effect on a solid metal. Concepts seems pretty similar to me though.

[Cynthia De Luna 4I]

threshold energy the mimum kinetic energy needed to turn kinetic energy into activation energy while the ionization energy is the energy needed to remove an electron

[Ulysis Baal 4J]

Like Alex said, the threshold energy is associated with the amount of energy required to remove an electron from a solid (via the photoelectric effect). As specified in the course reader, ionization energy refers to the amount of energy needed to remove an electron from an atom in its gaseous phase. I believe it is the phases that distinguishes the terminology, because additional energies get involved in removing an electron from a liquid/solid phase element compared to an element in the gaseous phase.