This dance is dedicated to the dancers in the San Francisco Bay Area who are still eager to dance Petronella after dancing for a full evening. Upon request, the musicians are often happy to play it after the final waltz, and commonly two or more sets spontaneously form and dance it eight times through with mostly-controlled abandon.  The title refers to the arrangement of electrons that occurs after energy is added to an atom or molecule. Such excited states are often unstable until they release the energy and return to the ground state.