Spectral lines Definition and 54 Threads

I don't really understand how we observe spectral lines of a particular element and why they are there? Can anyone help? Thanks.

The question: Given that w=h-bar(L+1)/I. Suppose that we observe spectral lines from the HCl molecule at wave numbers (in cm^-1) 85.03, 103.73, 124.30, 145.03, 165,51 and 185.86 (wavenumber here is simply in the inverse wavelength lambda^-1). What L values do these lines correspond to? My...

can anyone give me some good sites for spectral lines and understand how and why spectra occur. Possibly only using the bohr atom. I am a chemistry teacher in maryland, and I'm trying to find some good places so my students could do a search or look at some things online. any ideas...

I'm trying to understand this application of thermodynamics to astronomical inferrence. As I understand it, the temperature of a diffuse gas cloud in distant space can be inferred from the relative intensities of the spectral lines (correct?) which indicates the distribution of the population...