[lost]

A common question in the previous exam papers of my course is to approximate ionization energy of:

a) A hydrogen-like ion (i.e. one with only one electron) given the ionization energy of hydrogen.

b) An ion, given the longest wavelength in the highest frequency series of the spectrum of that ion.

It's probably a stupid question (ths is my first time taking Cemistry), but I've compared several textbooks, lecture notes and online databases, and am now more confused than when I started - as much of the information contradicts the rest.

Any help would be much appreciated...

[enahs]

http://en.wikipedia.org/wiki/Ionization_energy

For the longest wavelength question, you do the same thing, but you use the corresponding n for the highest value of that spectroscopic series and the lowest, the difference in the two is the energy for that transition.