Question

If the energy of H atom in the ground state is -E the velocity of photo electron emitted when a photon having energy E_p  strikes a stationary Li²⁺ ion in ground state is given by :

a) v=√[2(E_p - E)/m]

b) v=√[2(E_p- 9E)/m]

c) v=√[2(E_p - 9E)/m]

d) v=√[2(E_p - 3E)/m]

Answer 1

The correct option is (c) v=√[2(Ep - 9E)/m]

Work function for Li²⁺ =9E

E_p = w+ mv²/2

E_p= 9E +mv²/2

v=√[2(Ep - 9E)/m]