Question

A doubly ionized lithium atom is hydrogen like atom with atomic
. number 3. Find the wavelength of the radiation to excite the electron in
. `Li^(2+)` from the first to the third Bohr orbit. The ionization energy of the hydrogen
. Atom is 13.6V.
A. `134.25 Å`
B. `125.5 Å`
C. `113.7 Å`
D. `110 Å`

Answer 1

Correct Answer - C
Required energy `= [((-13.6)/(9))] - [((-13.6)/(1))] xx 9`
`= [13.6 - (13.6)/(9)] 9 = 8 xx 13.6 eV`
wavelength `= (12375)/(8 xx 13.6) = 113.7 Å`