=−3.4eV The energy of the emitted photon when an electron jumps from first excited state to ground state is
hυ=E2−E1=−3.4eV−(−13.6eV)=10.2eV
Maximum kinetic energy, Kmax=eVs=e×3.57V=3.57eV According to Einstein’s photoelectric equation Kmax=hυ−ϕ0 where ϕ0 is the work function and hv is the incident energy