Electron Arrangement

In IB chemistry, electrons are arranged in shells (energy levels), which contain sub shells (s,p,d,f)

The Hydrogen Spectrum provides evidence for this structure

A continuous spectrum contains all the wavelengths/frequencies/colour/energies of electromagnetic radiation
Hydrogen in a discharge tube shows a line spectrum, which contains only certain wavelengths/frequencies/colours/energies of electromagnetic radiation
The electron in hydrogen can be given extra energy by a fast moving electron in the discharge tube, which causes it to be promoted to a higher energy level
We can then see lines on the line spectrum of hydrogen at higher energy levels where the electron has been promoted
As we only see lines and not a continuous spectrum, this proves that the electron can only be in one place at one time, and so shells must exist.

End of this topic!

Drafted by Gina (Chemistry)