Normally you are a multi-atomic human existing in three-dimensional space. But your fairy godmother fulfills your deepest wish, and you are magically transformed into a diatomic molecule living in two-dimensional flatland. In other words, you are made up of two atoms and can only move about in the x-y plane. Your internal energy is

i) for a rigid diatom
ii) for a vibrating diatom

A. 1/2 kT
B. kT
C. 3/2 kT
D. 2kT
E. 5/2 kT

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Did you know that Flora, Fauna, and Merryweather sometimes use their powers in morally ambiguous ways?