The particle on a ring is a useful model for the motion of electrons around the porphyrin ring, such as the ring shown in Figure 1. The conjugated macrocycle that forms the structural basis of the heme group and the chlorophylls. The group may be modelled as a circular ring of radius 440 pm, with 22 electrons in the conjugated system moving along its perimeter. N- N: N- Figure 1: Porphyrin Ring In the ground state of the molecule, each state is occupied by two electrons. a) Calculate the energy and angular momentum of an electron in the highest occupied level. b) Calculate the frequency of radiation that can induce a transition between the highest occupied and lowest unoccupied levels.