Retinal is one of the many forms of vitamin A (the number of which varies from species to species). Retinal is a polyene chromophore, bound to proteins called opsins, and is a precursor to the pigment in the retinia responsible for animal vision. Retinal allows certain microorganisms to convert light into metabolic energy. The conjugated system of retinal consists of 11 C atoms and 1 oxygen atom. (As shown in the structure below): H3C CH3 CH3 CH O H3 a Model the conjugated Ï systern in retinal as a particle in a 1D box, assuming an average internuclear distance of 140 pm, what would be your length L of the box? The ground state of retinal contains doubly occupied levels up to n = 6, Calculate the energy difference between the ground and first excited state in which one electron is promoted to n = 7. b c) What frequency of radiation is required to produce a transition between these two states?