(a) Draw a rough schematic of the series of resonances corresponding to a vibrational transition for a diatomic. Label the P and R branches, explain what the difference is between them, and indicate what the spacing is between the resonance lines. (b) What is the main information about a diatomic molecule that one can obtain from vibrational and rotational transition frequencies (assuming that the reduced mass is known)?

The 3N-6 vibrational modes of a molecule can be sub-subdivided into three general types ofdeformations.(i) Define these and draw their approximate potential energy functions.  (ii) Order the three types. Start with the one requiring the least energy to animate.(iii) Where are anharmonic modes generally located in the energetic ordering relative toother modes and what other name(s) are they know by?  (iv) Discuss the significance of anharmonic modes and why accurately characterisingthem is key to precise energetic determinations and to accurately modellingspecificity, selectivity and functionality in chemical phenomena.

E rotational is 2.777×10−20 J

A molecule in a liqu id undergoes about 1.0 x 1013 collisions in each second. Suppose that every col lis ion is effective in deactivating the molecule vibrationally and that one coll ision in 200 is effective. Calculate the width (in cm-1) of vibrational transitions in the molecule.