Physik Line Spectra Klasse 12
Line Spectra
Emission Spectra Absorption Spectra
Energy Level Diagram: Example
• A photon with a specific energy & wavelength (E = h*f) • A photon with a specific energy & wavelength
is emitted by an excited atom (E = h * f = h * c/λ) is absorbed by an atom
• An excited atom is an atom where an e- is in a higher • An e- is excited and jumps onto a higher energy level
energy level (the e- is in an excited state & the gas is an excited gas)
• The e- can jump one or more energy levels depending
• The e- is unstable in will fall to the next possible lower
on the energy of the photon
energy level • The e- is unstable and will therefore fall to the next
• By doing so the atom will emit a photon with a specific possible energy level
wavelength & energy (the energy difference between • By doing so it emits a photon with the energy of the
the two energy levels) energy difference between the two levels
• The photons can be observed on an emission • This photon is emitted in a random direction
spectrum • The possibility that the photon will travel in the same
• The lines on an emission spectrum are discrete” which direction as the original photon is very small
means they are specific for the element • This is the reason why there are dark lines in an
absorption spectrum
• These lines are “discrete” which means they are
specific for the element
Line Spectra
Emission Spectra Absorption Spectra
Energy Level Diagram: Example
• A photon with a specific energy & wavelength (E = h*f) • A photon with a specific energy & wavelength
is emitted by an excited atom (E = h * f = h * c/λ) is absorbed by an atom
• An excited atom is an atom where an e- is in a higher • An e- is excited and jumps onto a higher energy level
energy level (the e- is in an excited state & the gas is an excited gas)
• The e- can jump one or more energy levels depending
• The e- is unstable in will fall to the next possible lower
on the energy of the photon
energy level • The e- is unstable and will therefore fall to the next
• By doing so the atom will emit a photon with a specific possible energy level
wavelength & energy (the energy difference between • By doing so it emits a photon with the energy of the
the two energy levels) energy difference between the two levels
• The photons can be observed on an emission • This photon is emitted in a random direction
spectrum • The possibility that the photon will travel in the same
• The lines on an emission spectrum are discrete” which direction as the original photon is very small
means they are specific for the element • This is the reason why there are dark lines in an
absorption spectrum
• These lines are “discrete” which means they are
specific for the element
