Number of energy levels.... I have been told that as were go further away from the nucleus, the energy levels get closer and closer together - do we get to a stage where we get no more? I assume we must because any energy above this causes the substance to ionise (ie the ionisation energy); but are there an infinate number of energy levels before this or some discrete number of them? I have been told that the way that the levels get closer and closer together is governed by some equation - what I guess I'm asking boils down to is is this an infinate geometric progression with the levels getting closer and closer for infinity (ie - an infinate number of levels), or do we get to a point where an equation would just give the same answer - there are no more levels which exist? Thanks in advance.