The total energy of an electron in the first excited state of the hydrogen atom is about - 3.4 eV.
(a) What is the kinetic energy of the electron in this state ?
(b) What is the potential energy of the electron in this state ?
Which of the answers above would change if the choice of the zero of potential energy is changed ?

Explanation

It is given here that total energy of an electron in the first exctied state of the hydrogen atom is ` - 3.4 eV. Thus E = - 3.4 eV`.
(a) `therefore ` K.E of the electron in this state `K = - E + 3.4 eV.`
(b) `therefore ` Poteintial energy of the electron in this state `U = 2K = - 6.8e V`
(c) kinetic energy does not depend upon the choice of zero of potential energy and remains unaffected .
However , value of potential energy and ,consequently , value of the total energy of electron depends upon the choice of zero poteintial energy . Hence , on changing zero of potential energy values of LI and E will change.