## Absorption Spectrum

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

Alan Wu
Posts: 61
Joined: Sat Sep 14, 2019 12:16 am

### Absorption Spectrum

I don't get why only EMs of specific wavelengths can be absorbed by Hydrogen atoms. I understand that the Emission Spectrum is a result of electrons falling back from one specific energy level to another. However, why can only specific wavelengths be absorbed? If the EM has a short wavelength and the energy is really high, shouldn't it be able to excite the electron to a higher energy level anyways? Why is it not absorbed then?

Jessica Tejero 3L
Posts: 54
Joined: Wed Sep 25, 2019 12:16 am

### Re: Absorption Spectrum

I think its because wavelength of light comes from photons with a specific energy released by electrons making transitions between specific energy levels of the atom.When an electron in an atom goes from a higher energy level to a lower energy level, it gives a photon to carry off the extra energy. The energy is equal to the energy difference between the two energy levels and the frequency will give the specific color. Absorption can't happen if the photon energy does not correspond to the difference between two energy levels.