A hydrogen atom in a state of binding energy 0.85 eV makes a transtition to a state of excitation energy of 10.2 eV.
(i) What is the initial state of hydrogen atom?
(ii) What is the final state of hydrogen atom ?
(iii) What is the wavelength of the photon emitted ?

Explanation

Let `n_(1)` be initial state of electron. Then
`E_(1)=-(13.6)/(n_(1)^(2))eV` Here `E_(1)=-0.85eV`, therefore
`-0.85=-(13.6)/(n_(1)^(2))` or `n_(1)=4`