How much energy is required to ionise a hydrogen atom if the electron occupies n=5 orbit ? Compare your answer with the ionisation energy of hydrogen atom (energy required to remove the electron from n=1 orbit).

How much energy is required to ionise a hydrogen atom if the electron

1.	How much energy is required to ionise a hydrogen atom if the electron occupies n=5 orbit ? Compare your answer with the ionisation energy of hydrogen atom (energy required to remove the electron from n=1 orbit).
Answer» Solution :`E_(n)=-(21.8xx10^(-19))/n^(2)" J ATOM"^(-1)` For ionization from 5TH ORBIT, `n_(1)=5, n_(2)=OO` `:. Delta E=E_(2)-E_(1)=-21.8xx10^(-19) (1/n_(2)^(2)-1/n_(1)^(2))=21.8xx10^(-19) (1/n_(1)^(2)-1/n_(2)^(2))=21.8xx10^(-19) (1/5^(2) -1/oo)` `=8.72xx10^(-20) J` For ionization from 1st orbit, `n_(1)=1, n_(2)=oo` `Delta E'=21.8xx10^(-19) (1/1^(2)-1/oo)=21.8xx10^(-19) J` `(Delta E')/(Delta E)=(21.8xx10^(-19))/(8.72xx10^(-20))=25` Thus, the energy required to remove electron from 1st orbit is 25 times than that required to remove electron from 5th orbit.