Visible light cannot eject photo electrons from copper metal, whose work function is 4.4 e V. Why? Prove it mathematically.

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

Radiation of wavelength 180 nm ejects photoelectrons from a plate whose work funcion is 2.0 eV. If uniform magnetic field of flux density 5.0 xx 10^-5 T is applied parallel to the plate, what should be the radius of the path followed by electrons ejected normally from the plate with maximum energy.

Light of wavelength 500 nm falls on a metal whose work function is 1.9 eV. find the energy of the Photon in eV

A light source of wavelength lambda illuminates a metal and ejects photoelectron with (KE)^(max) = 1 eV. Another light source of wave length (lambda)/(3), ejects photoelectrons from same metal with (KE)^(max)=5 eV. Find the value of work function (eV) of metal.

It is harder to remove free electrons from copper than from sodium. Which has higher work function.

Blue light can eject electrons from a photo sensitive surface while orange light can not. Will violet and red light eject electrons from the metal surface?