Estimate the size of the fine structure of the 2p conguration in hydrogen-like
sodium (i.e. sodium ions with all but the last electron removed). Why can't we use
perturbation theory to calculate the effect of the spin-orbit interaction in hydrogen-like uranium?
The Attempt at a Solution
I don't understand what the question means! Is it looking for a literal size of some sort, or does it want the size of the energy change from the energy of a Gross Structure state to a petrubed state?
How would you read this question?