Photodissociation of hydrogen at ground state requires a 273nm wavelength for a photon particle to dissociate H2--> H- + H+. But what about hydrogen at higher states of energy? Is the 273nm a constant? If not, what is the formula for min. wavelength for higher energy states (frequency-temperature relationship)? I've researched this quite a bit, but I can't find the answer I'm looking for.