Is there ever a negative frequency

[charlotte_jacobs_4I]

For Rydberg's equation should the answer ever be negative? What if you go from n=4 to n=2 or n=3 to n=5?

[skyeblee2F]

There is no such thing as a negative wavelength or frequency. The negative sign you may calculate using Rydberg's equation is simply a representation of energy being either released or emitted and can be ignored in terms of frequency. Going from n=4 to n=2 emits energy, so the equation yields a negative answer. But, again, you can ignore this if you are trying to calculate frequency or wavelength.