Answer Happy

Question 4 (i) (ii) Describe how band heads in the spectrum of an electronic transition in a diatomic molecule can be formed (hint: Fortrat diagrams). [4 marks] Given that the energy separation between the lowest two rotational levels in H, is 0.0151 eV (121.8 cm) and that the separation between the two lowest two vibrational levels is 0.53 eV (4275 cm-'), (a) calculate the separation between the lowest two rotational levels of the HD and D2 molecules, [2 marks] calculate the separation between the lowest two vibrational levels of the HD and D2 molecules, and [2 marks] estimate the number of rotational states between the lowest two vibrational states of H2 (the equilibrium internuclear separation in a H, molecule is 7.4 x 10-"m) [2 marks (b) (c)