1. The problem statement, all variables and given/known data In the spectrum of the blue part in a candle flame, there’s a violet emission at 432 nm due to excited CH* molecules (chemiluminescence). Why 432? Why not 400 or 500? There are emissions at 436, 475 and 520 nm too. Why these numbers? 2. The attempt at a solution Is it because the energies of the photons emitted correspond to these wavelengths, as E = hc/λ?