Electrons of energy 12.09eV can excite hydrogen atoms. To which orbit is the electron in hydrogen atom raised and what are the wavelength of the radiations emitted as it drop back to ground state?

Hey Student..
As per what is required in this question, you need to take into account the basic formula of electron exication in the case of hydrogen atom.
first try calculating the energy of electron in the first orbit and then use the formula given by Rydberg to get the answer for the question