MARY - Topic 2 Flashcards
How do we create a continuous spectrum?
When an electric discharge is passed through hydrogen gas, it will split H2 molecules into H atoms, and the electrons within these atoms become excited.
As the excited electrons relax from their excited states back to their ground states, they emit energy which produces light in the visible EM region.
When this emitted light is passed through a prism, only certain specific frequencies are observed.
Fixed frequencies mean fixed energies, so the energy levels of these electronic transitions are quantised.
What does a RH equal?
13.6 eV
What is the balmer series?
The hydrogen emission frequencies observed in the visible region of the EM spectrum?
n1 = 1
Lyman
n1 = 3
Paschen
n1 = 4
Brackett
n1 = 5
Pfund
What is an emission spectrum?
Contains coloured lines on a black background.
What is an absorption spectrum?
Black lines on a coloured background, where energy is absorbed from the EM radiation to promote an electron from the lowest energy state (ground state) to a higher energy state (excited state).
How do spectra show that transitions are quantised?
The line positions in both the emission and absorption spectra correspond in frequency.
What does 1eV = ?
1.602 x 10^-19 J
What does 1J = ?
kgm2s-2
