A hydrogen atom is excited to a higher energy level and then allowed to return to…
PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
A hydrogen atom is excited to a higher energy level and then allowed to return to lower levels.
(i) Explain with reason why photons are emitted only when the electron makes a downward transition between two permitted energy levels.
(ii) An electron is initially in the third energy level (n=3). List all the distinct downward transitions that can occur until the electron finally reaches the ground state.
(iii) Using the list obtained in part (ii), show how many different spectral lines can be observed for this case, and give a brief reason why no additional lines are possible once the electron reaches the first level.