‘ “We still don’t get ‘renaissance structures,’”
Said the students in moments past lecture.
Their phrasing, inverted,
To me then asserted
Historic’lly wondrous conjectures.’
Since the April 28 limerick was summarized a few days ago for Graduation 2020, this entry returns to the home stretch of my poetic project. The 29 April 2019 limerick addresses an imaginative misphrasing that I’ve encountered a few times in teaching.
‘ “We still don’t get ‘renaissance structures,’” /
Said the students in moments past lecture…’
A common misstatement in General Chemistry is the use of “renaissance structures” for “resonance structures.” (Presumably, this error would be characterized as some variant of spoonerism or mondegreen!)
Resonance structures acknowledge the limitations of simple drawings in representing chemical reality. Chemists use Lewis structures, or electron-dot structures, as a first step towards depicting molecular structures. In certain cases, a molecule can exhibit resonance, which means that one single Lewis structure cannot fully depict the complexities of the molecule’s bonding. In these cases, multiple resonance structures are drawn, and a chemist considers the true molecular structure to be an average of the resonance structures, also known as a resonance hybrid.
Often, resonance constitutes a challenging concept, especially if students have not encountered it previously. Moreover, I often notice that some of the best discussion in class arises at the close, in the few minutes when students ask questions in passing, before heading out the door.
‘Their phrasing, inverted, /
To me then asserted /
Historic’lly wondrous conjectures.’
In several years of teaching, I have heard the “renaissance structure” description several times. I always appreciate the flipped-syllable phrasing, which provides a diverting vision of complex Renaissance architecture… in the midst of my decidedly non-complex molecular drawings.
“Resonance theory” arises in multiple contexts throughout the curriculum. As with many scientific phrases, it exhibits an interesting duality: standing alone, it is an evocative phrase; in the chemistry context, it has a specific meaning. I’ve attempted throughout this project to build on both aspects: balancing the poetic-sounding terms of my disciplinary vocabulary with information about their technical definitions.
Chemphasis 