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Clara Chung
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For example a metal atom have 3 electrons which occupies 2 energy level. Is the threshold frequency = the energy needed to bring an electron in E2 to E(infinity) / h?
Clara Chung said:For example a metal atom have 3 electrons which occupies 2 energy level. Is the threshold frequency = the energy needed to bring an electron in E2 to E(infinity) / h?
Thanks for telling me that an atom from a metal has different properties from a metal.ZapperZ said:You need to understand one very important concept here. When atoms are together to form a solid, many of the individual properties of isolated atoms are no longer relevant. A solid has many properties that an individual atom does not have. This includes the formation of "energy bands" in solids, whereas in atoms, you have discrete energy levels.
So your question here doesn't make any sense because you are asking a question about a "metal", which is a solid, based on the valence shell of an individual atom. While this may be relevant when one probes deeper energy state of the metal, it is no longer relevant when you talk about "threshold" frequency or energy to cause the first ionization.
For example, the first ionization energy of Cu atom is ~7.7 eV. Yet, for Cu metal, the work function, and thus, the threshold energy for photoemission, is ~4.6 eV. These two numbers are different!
More is Different! Solid state physics is not simply "a lot of atomic physics".
Zz.
The threshold frequency is the minimum frequency of light required to cause the emission of electrons from a metal surface.
The threshold frequency is directly proportional to the work function of a metal. As the work function increases, so does the threshold frequency.
Yes, the threshold frequency can be calculated using the equation f = work function / Planck's constant.
The intensity of light does not affect the threshold frequency. As long as the frequency of light is equal to or greater than the threshold frequency, electrons will be emitted from the metal surface.
The threshold frequency is important because it determines whether or not the photoelectric effect will occur. If the frequency of light is below the threshold frequency, no electrons will be emitted regardless of the intensity of the light.