Green light ejects electrons from a certain photosensitive surface, yellow light does not. Will red and violet light eject electrons from the same surface?

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?

Work function of a metl surface is 4.2 eV. The maximum wavelength which can eject electrons from this metal surface is:

Find the frequency of light which ejects electrons from a metal surface, fully stopped by a retarding potential of 3 V. The photoelectric effect brings in this metal at a frequency of 6 xx 10^14 Hz . Find the work function for this metal (Given h=6.63 xx 10^-34 Js) /

Explain two ways of emission of electrons from metal surfaces.