Turn over 9 11 An electron in its ground state absorbs electromagnetic radiation of wavelength λ. The energy level diagram represents the resulting energy transition of the electron. ground state n = 1 −10.8 eV −6.5 eV n = 3 n = 2 (a) Calculate the wavelength of radiation absorbed by the electron. (3) .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. Wavelength = ....................................................... (b) The electron eventually returns to its ground state. Explain, with reference to the energy level diagram, how this may result in the emission of radiation with a longer wavelength than λ. (3) .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. (Total for Question 11 = 6 marks)