How does uncertainty relation accountfor natural width of spectral lin

1.	How does uncertainty relation accountfor natural width of spectral lines?
Answer» Uncertainty principle: Energy level above ground state with energy E and lifetime Δt, has uncertainty in energy: ΔEΔt ~h/2π i.e. short-lived states have large uncertainties in the energy. • A photon emitted in a transition from thislevel to the ground state will have a range of possible frequencies: Δυ=1/(2πΔt) which account for the natural line width of spectral lines.

How does uncertainty relation accountfor natural width of spectral lines?

Answer»

Uncertainty principle: Energy level above ground state with energy E and lifetime Δt, has uncertainty in energy:

ΔEΔt ~h/2π

i.e. short-lived states have large uncertainties in the energy.

• A photon emitted in a transition from thislevel to the ground state will have a range of possible frequencies:

Δυ=1/(2πΔt) which account for the natural line width of spectral lines.