## Emission v Absorption Lines

H-Atom ($E_{n}=-\frac{hR}{n^{2}}$)

emmajanibekyan_4I
Posts: 17
Joined: Wed Sep 21, 2016 2:57 pm

### Emission v Absorption Lines

What do lines exactly represent in hydrogen(or any element really) emission or absorption spectra? Do they represent wavelengths or frequencies being absorbed or emitted respectively? I've watched the video modules and everything, I just really want a direct answer to this to clear some stuff up, because the post assessment surveys online don't provide for answers at the end. Thank you in advance.

Emerald Ellspermann 1K
Posts: 28
Joined: Wed Sep 21, 2016 3:00 pm
Been upvoted: 2 times

### Re: Emission v Absorption Lines

The lines on an emission spectrum indicate the wavelengths of light that a substance can emit. The lines on an absorption spectrum indicate the wavelengths of light that a substance can absorb.

Simon Kapler 3I
Posts: 15
Joined: Mon Sep 26, 2016 3:01 am

### Re: Emission v Absorption Lines

The other response is completely correct. However, a helpful connection to make is that the absorption and emission spectra represent the same thing. The absorption spectrum of an element will appear to be a full "rainbow" with a few black stripes occurring at certain wavelengths. For the emission spectrum of the same element, the spectrum will appear to be mostly black, with a few stripes of color at certain wavelengths (corresponding to the black stripes on the absorption spectrum). If you were to lay the absorption spectrum of an element on top of its emission spectrum, there would be no breaks in the color of the spectrum. The only difference between absorption and emission spectra is whether they are indicating which wavelengths have been absorbed by the atom (absorption spectrum, with black lines at the wavelengths at which light is absorbed), or the wavelengths of light that have been given off by an excited atom (emission spectrum, with lines of color against an otherwise black background).