A continuous spectrum of light is incident on a cloud of hydrogen gas
PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
A continuous spectrum of light is incident on a cloud of hydrogen gas. After passing through the gas, it is observed using a spectrometer.
(1) Explain why the light observed contains dark lines in the continuous spectrum.
(2) One of the dark lines in the spectrum has a wavelength of 434 nm. Calculate the energy of a photon of light with this wavelength. Give your answer in eV.
(3) Outline how astronomers can use their observations of the dark lines in the spectra from stars to find information about the composition of the stars.