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Photoelectric Effect? Challenging Physics problem?
Lithium, tungsten, and silver have work functions of 2.3 eV, 4.58 eV, and 4.73 eV, respectively. 277 nm light is incident on each ofthese metals. Which of these metals will exhibit the photoelectric effect? The speed of light is 3 × 108 m/s and Planck’s constant is 6.63 × 10−34 J • s .
1. lithium
2. tungsten
3. tungsten and silver
4. silver
5. lithium and tungsten
6. None of these
Part 2
For those metals that do exhibit the photoelectric effect, what is the maximum kinetic energy of the photoelectrons? Answer in units of eV.
1 Answer
- debydeteLv 71 decade agoFavorite Answer
Calculate the energy of the photon from;
E = hc/D (D is the given wavelength in meters)
This will come out in Joules so divide by 1.6x10^-19 , to get the energy in eV.
Compare the photon energy with the given work functions. If it is larger then you'll have a photo electric effect.
The max KE of the emitted electrons will be the difference between the photon energy and the work function.
