When a hydrogen atom is excited from ground state to first excited state, then

Options

A. its kinetic energy increses by `10.2eV`
B. its kinetic energy decrease by `10.2eV`
C. its potential energy increases by `20.4eV`
D. its angular momentum increasedby `1.05xx10^(-34) j-s` .

Answer

A, C, D

Explanation

`K.E=(13.6)/n^(2)eV,P.E.=(-2(13.6))/n^(2)eV`
for hydrogen `Z=1: DeltaK=K_(f)-K_(1)`
` DeltaK.E=13.6[1/(2)^(2)-1/(1)^(2)]=10.2eV(decrease)`
=`(PE)_(f)-(PE)_(i)`
` DeltaP.E.=-2(13.6)[1/(2)^(2)-1/(1)^(2)]=20.4eV`
(increase)
Angular momentum `L=(nh)/(2pi)`
` DaltaL=h/(2pi)(2-1)=h/(2pi)=1.05xx10^(-34)` j-s(increase)`