Quantum mechanic

The allowed energy levels (En) for a particle of mass m in a one-dimensional box of length a are given by: En = n2h2/(8ma2) , n = 1, 2, 3, ... The carbocyanine dye 1 has 10 electrons in the conjugated π-system (highlighted in bold). The energy levels (“orbital energies”) of the π-electrons can be estimated by treating the πsystem as a one-dimensional box of length 1.40 nm. Each level can then be occupied by up to 2 electrons. 1 Calculate the energy difference between 5th and 6th energy levels (i.e., the gap between the highest occupied and lowest unoccupied orbitals). Convert this energy to a wavelength, λ. The actual absorption wavelength is 575 nm. Comment on why the result of your calculation is different from this. h = 6.626 × 10–34 J s, me = 9.109 × 10–31 kg, c = 2.997 × 108 m s–1

Here's just a quick bit of working out on this one (hopefully the attachments work)

The reason the wavelength aren't identical is because the particle in a box is a very simplified model and so it can't be expected to completely agree with the reality of the situation, given that fact, the agreement you get is quite good

Thank You, but it was few days ago and I have already done it

Ahh well, never mind