Write Einstein's photoelectric equation . State clearly the three salient features observe in photoelectric effect , which can be explained on the basis of the above equation .

Explanation

Einstein's photoelectric equation:
`K_(max)=(1)/(2)mv_(max)^(2)=hv=phi0`
where `phi_(0)` is work function
(i) A part of the energy of the photon is used in liberating the electron from the metal surface which is equal to the work function `phi_(0)` of the metal.
(ii) The rest of energy of the photon is used to get the maximum kinetic energy `K_(max)` to the emitted photo electron.