The ionisation enthalpy of hydrogen atom is `1.312xx10^(6)J*mol^(-1)`. The energy required to excited the electron in the atom from n=1 to n=2 is-

Options

A. `8.51 xx 10^5 J mol^-1`
B. `6.56 xx 10^5 J mol^-1`
C. `7.56 xx 10^5 J mol^-1`
D. `9.84 xx 10^5 J mol^-1`

Answer

D

Explanation

(d) `Delta E = E_2 - E_1 = - (E_1)/(2^2) + (E_1)/(l^2)`
=`-(1.312 xx 10^6)/(2^2) + 1.312 xx 10^6`
=`9.84 xx 10^5 J mol^-1`.