Posted by Kate on .
If a Li 2+ ion, initially in the 2nd excited state absorbs a photon of light with a fequency of 2.82 X 10^6 GHz, what will be the final energy level for this electron? Show all stepts to get final energy level.
i have no clue what this question is even asking :[?

AP CHEMISTRY 
drwls,
Use the formula
h*frequency = E to get the energy of the photon
h is Planck's constant.
The energy of the n=2 state is
E2 = R/2^2 = R/4
R is the Rydberg constant for Li, expfressed in Joules. It equals 9 time the Rydberg cosntant of hydrogen, because of the Z=3 charge of the nucleus.
Use the formula
E = En  E2 to get the energy of the upper state
Then use
En = R/n^2 to get the upper level quantum number, n.
If you find the Rydberg constant expressed in wave numbers (cm^1) instead of Joules, follow the same procedure but use the wave number of the transition (1/wavelength) instead of the energy of the photon, E.
h c * wavenumber = energy