A) describe and sketch the vibrational energy levels observed for diatomic molecules in the harmonic oscillator approximation, using an appropriate formula to support your answer (4 marks) b) state the selection rules for ir transitions in diatomic molecules. (2 marks) c) briefly explain the implications of anharmonicity for vibrational spectra, with particular reference to the selection rules for diatomic molecules, and the resultant energy levels and spectra observed.

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.

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