Hello, I have a question regarding discrete energy levels of atoms. If electrons must inhabit certain energy levels, when they are excited up to a higher energy level, do they instantaneously jump to that level, or do they exist for some short time 'in between'? Furthermore, if the wavefunction of an electron extends over space (infinitely far?), does it really mean that there is the highest probability that the electron inhabits the energy level, or does an energy level correspond to a large 'space'? We've been looking at the bohr model which would suggest that these energy levels must exist on equipotential lines, but I remember from A-level chemistry the shape of different orbitals and clearly something else is going on here... I know that's a bit of a loose question, but i'd enjoy a wide ranging answer :) Thanks!