Calculate the threshold wavelength of photons, which can emit photoelectrons from cesium. Given that work function of cesium=1.8 eV.

The work function of sodium is 2.3 eV. Calculate the maximum wavelength for the light that will cause photoelectrons to be emitted from sodium.

Light from a dicharge tube containing hydrogen atoms falls on the surface of sodium.The kinetic energy of the fastest electrons emitted from sodium is 0.73 eV.The work function for sodium is 1.82 eV. Find the energy of the photons causing the photoelectric emission,

Light from a dicharge tube containing hydrogen atoms falls on the surface of sodium.The kinetic energy of the fastest electrons emitted from sodium is 0.73 eV.The work function for sodium is 1.82 eV.find the quantum numbers of the two levels involved in the emission of these photons,

Find the maximum wavelength of electromagnetic radiation,which can create a hole-electron pair in germanium.Given that forbidden energy gap in germanium is 0.72 eV.

Visible light cannot eject photoelectrons from copper surface, whose work function is 4.4 eV. Why? Prove it mathematically.

X-rays of wavelength lambda fall on an phtot senstive surface,emitting electrons.Assuming that the work function of the surface can be netglected,prove that the de-Broglie wavelength of electrons emited will be sqrt(h lambda//(2 m c)) .

Energy band gap of gallium arsenide phosphate is 1.98 eV.Calculate the wavelength of electromagnetic radiation emitted,when electrons and holes combine in this alloy semiconductor directly.