Maximum energy is evolved during which of the following transitions ?

Options

A. n=1 to n=2
B. n=2 to n=6
C. n=2 to n=1
D. n=6 to n=2

Answer

C

Explanation

When transition is from upper state to lower state, the energy is evovled. Energy is emitted only when an electron jumps from an outer stationary orbit of energy `E_(2)` to inner stationary orbit of energy `E_(1)`. The energy emitted `E=E_(2)-E_(1)`.
In option (c),
`E=-Rhc((1)/(1^(2))-(1)/(2^(2)))=-(3)/(4)Rhc`
In option (d), `E=-Rhc((1)/(2^(2))-(1)/(6^(2)))=-(2)/(9)Rhc`
the process in which absorption of energy by an electron takes the electron from an inner orbit to some outer orbit of higher energy is called excitation.