I noticed that the hydrogen spectral lines are grouped into 6 series and given a value for n. I also noticed that each series was named after its discoverer but "coincidentally?" falls into a specific region of the EM spectrum so the Lyman series (n=1) of lines are all in the UV region, the Balmer series (n=2) in the visible region, the Paschen series (n=3) the IR region etc. Firstly is this "n" the principle quantum number? If so what have these series' got to do with the different energy shells of the Bohr model? For example what has the balmer series got to do with the 2nd energy shell? Finally what is it about this correlation that causes the lines of each series to appear where they do. For example why do the lines all appear in the UV region when n=1 but lie in the visible region when n=2?