[Sanada]

From the information below identify element x:
A. The wavelength of the radio waves sent by an FM station brodcasting at 97.1 MHz is 30 million times greater than the wavelength corresponding to the energy difference between a particular excited state of the hydrogen atom and the ground state.
B. Let "M" represent the principal number for the valence shell of element x. If an electron in the hydrogen atom falls from the shell "M" to the inner shell corresponding to the excited state mentioned above in part A, the wavelength of light emiited is the same as the wavelength of an electron moving at the speed of 570m/s
C. The number of unpaired electrons for element X in the ground state is the same as the maximum number of electons in an atom that can have the quantum number designations: n=2, ml=-1, m=-1/2
D. Let A equal the charge of the stable ion that would form when the undiscovered element 120 forms ionic compounds. This value of A also represents the angular (or azimuthal) quantum number for the subshell containing the unpaired electron(s) for element X.

I was looking for some help with parts b and d and I was wondering if anyone could tell me if what I did in part A and C seems to be correct or at least headed in the right direction.
for part a. I used wavelength=c/v and converted Mhz to hz. I then divided this value to by 30 million and used the E=hc/wavelength to get that the energy change = 1.93e-18 I used a hydrogen excited chart thing... and found the closest n value energy change to be from 3 to 1?
for part b I think that finding the energy from the part b with part a would give me an energy level at something particularally useful but I don't know how to start or what it would be used for?
for part C I think by the values that the element is either Mn,Tc,Re, or Bh?
part D absolutely makes no sense to me...

Any help with parts B and D especially or just a start would be greatly appreciated

[Yggdrasil]

For part B, you will probably need the equation for the de Broglie wavelength of a particle:
http://en.wikipedia.org/wiki/Wave-particle_duality#de_Broglie.27s_hypothesis

For part C, you want to find out the possible sets of quantum numbers (n, l, m_l, m_s) where n = 2, m_l = -1, and m₂ = -1/2.  The answer should be a number and not an element.

For part D, think of where (i.e. in which column) element 120 would fall on the periodic table.

Good luck.