I learnt that two lines in the emission spectrum of Sodium, namely ## D_1 ## and ## D_2 ##, are on the visible region of the spectrum. Can I obtain these lines from a Sodium vapour lamp? I want to use a prism to separate out the individual wavelengths, a no then use a photographic film to obtain the spectrum on a screen. In this case, will I be able to see the two lines? Please note that I want to conduct this experiment in my school laboratory. So, I don't have very good instruments other than a simple student spectrometer, which is used to determine the angle of prism and it's minimum deviation. It is for the use of this spectrometer that the school lab has a Sodium vapour lamp.