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Science Poetry

Words of the Week

“Today starts a week that will readily  
Spotlight highlights for seven days, steadily,
As we celebrate nationally
Our science that rationally
Explores matter’s properties: chemistry.”

The 20 October 2019 Twitter poem began a series of poems written to celebrate National Chemistry Week 2019.    

“Today starts a week that will readily /
Spotlight highlights for seven days, steadily…”
As with Chemists Celebrate Earth Week, which I’ve written about in this space previously, National Chemistry Week is a celebration sponsored by the American Chemical Society.  I had not realized its longevity until writing this piece; the first occurrence was in 1989.  Each year, the week has a different theme, highlighting such myriad topics as chemistry and art, environmental chemistry, and nanotechnology.    

“As we celebrate nationally /
Our science that rationally /
Explores matter’s properties: chemistry.”
The theme of the 2019 National Chemistry Week was “Marvelous Metals,” as will be seen over several upcoming entries here.  This year, National Chemistry Week will be held from October 18-24 and will focus on “Sticking with Chemistry”: the science behind glues and adhesives.  The American Chemical Society provides a wealth of educational resources and activities each year to celebrate the pertinent theme, sponsoring events across the USA.  Chemistry examines the structures, properties, and reactions of chemical species, commonly phrased as the study of matter.    

(“Chemistry” is a word that doesn’t perfectly rhyme with too many others.  One of the rhymes I tried in an early draft of this limerick was “centrally,” building on chemistry’s characterization as a “central science.”  I was most familiar with this phrase in its capacity as part of a popular textbook title; again, it was interesting in drafting this essay to realize some larger discussions of that phrase.  As one might suspect, the connections between different STEM disciplines are complex and oft-debated!)   

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Science Poetry

Shaping Ideas

“To consider electrons’ repulsions
In geometries under construction,
VSEPR theory
Provides first steps; here, see 
To molecular shapes, introduction.”  

The 14 October 2019 limerick alludes to a theory used in introductory chemistry courses to rationalize molecular geometries.   

“To consider electrons’ repulsions /
In geometries under construction…”
Yet another big idea in General Chemistry is that of molecular geometry: the three-dimensional shape in which a molecule exists.  The shapes of molecules have major implications for how these molecules can react and interact with one another, and so being able to predict a molecule’s geometry is an important first step for understanding its properties and reactions.  Three theories are typically introduced to rationalize molecular geometries: valence bond theory, molecular orbital theory, and valence-shell electron-pair repulsion theory.  All involve to some extent the central idea that negatively charged electrons repel one another.  

“VSEPR theory / 
Provides first steps; here, see /
To molecular shapes, introduction.”     
In general chemistry textbooks, the chapter on molecular geometry is a chapter in which Bent’s characterization of “strange terms for strange things” often seems particularly apt.  The three theories mentioned above are referred to as their abbreviations: VB theory, MO theory, and VSEPR theory, respectively.  (Further confusing the issue, VSEPR is often pronounced “vesper”!  However, in this poem, the rhyme scheme relies on spelling out the acronym.)       

VSEPR theory is the simplest of the three and is generally extensively explored in introductory coursework, providing important “first steps.”  As alluded to above, VSEPR stands for “valence-shell electron-pair repulsion.”  Valence electrons are the outermost electrons of an element; when elements combine into molecular compounds, the valence electrons participate in covalent bonds (with each bond involving two electrons) or exist in “lone pairs.”  In all of these cases, the electron pairs from the valence shells repel.  This ultimately results in characteristic shapes for molecules, as electron pairs will distance as far away from one another as is geometrically possible.   

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Science Poetry

Evenhanded Remarks

“The property known as chirality:
A helix’s handed spirality;
Two non-superposing
Mirrored molecules, chosen
To label by dext/sinist-rality.”  

The 23 September 2019 limerick addressed an interesting property observed in three-dimensional molecules, which is introduced in organic chemistry coursework.   

“The property known as chirality: /
A helix’s handed spirality…”
Organic Chemistry 1 is a challenging course for many reasons, one of which is the necessity of thinking about three-dimensional molecules and properties via largely two-dimensional communication: textbooks and chalkboard drawings.  One property that demands the ability to think three-dimensionally is chirality.  

It is obvious when someone puts shoes on the wrong foot or gloves on the wrong hand.  Feet and hands are chiral: they are non-superimposable mirror images.  Some molecules exist in “handed” forms, which means they react differently in “glove-like” chemical environments: some fit and some don’t.  Other molecules are achiral; they do not exhibit this quality.  (I’ve always liked the succinctness of “shoes are chiral; socks are achiral.”)   A DNA molecule, with its spiraling helix, is chiral, providing a pertinent rhyme.

“Two non-superposing /
Mirrored molecules, chosen /
To label by dext/sinist-rality.” 
Several precise vocabulary terms are introduced via topics of stereochemistry.  Molecules that are stereoisomers are molecules made up of the same atoms bonded in the same order but with different three-dimensional arrangements.  Stereoisomers that exist as pairs of the non-superimposable mirror images described above are called enantiomers.  Specific stereocenters (locations where chirality is evident) are distinguished as having “R” or “S” orientations.   Many such terms are used in organic coursework.    

Along with R/S notation, chiral molecules can also be described in terms of their optical rotation: the direction in which they rotate plane-polarized light, which is described with a positive or negative sign.  These terms are dextrorotatory (clockwise rotation) and levorotatory (counterclockwise rotation).  To fit the limerick’s rhythmic constraints, “dext/sinist-rality” was used as a shorthand for this last set of “handed” definitions.    

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Science Poetry

Addressing Challenges

“Quantum numbers disencumber
Orbital descriptions.  
Combinations’ denotations: 
3-D space depictions
From wavefunctions.  Numbers’ junctions 
Address volumes probable.
Useful tools are Q. N. rules,
To name electrons’ ‘domiciles.’”

The 16 September 2019 Twitter poem highlights a useful metaphor for considering atomic orbitals (mathematical functions that describe electron behaviors) in General Chemistry.  Since the actual math describing atomic orbitals will not be seen until higher-level chemistry coursework, it can be challenging to discern the uses and descriptions of these models at the introductory level.  

“Quantum numbers disencumber /
Orbital descriptions.”  
Matter functions differently from our everyday experience at the atomic and subatomic scales: whereas the equations of classical mechanics work well in describing everyday observations, the equations of quantum mechanics are used to describe the particulate-level scale.  Electrons are subatomic particles, and their locations are described in terms of probabilities; rather than the exact path delineated by an “orbit,” an electron’s location is within an “orbital.”  An orbital is described by a combination of quantum numbers (n, l, and ml).  Each number relates to a different aspect of the orbital: combined, they establish its size, shape, and orientation in space.  (A final quantum number, ms, identifies the specific electron within its orbital, via that electron’s spin.)  A combination of quantum numbers specifies an orbital of interest, “disencumber[ing]” its description.   

“Combinations’ denotations: /
3-D space depictions /
From wavefunctions.  Numbers’ junctions /
Address volumes probable.”    
By manipulating the mathematical function associated with an orbital (called a wavefunction), a three-dimensional shape results; this shape represents, with 95% certainty, where an electron will be.  Each specific “3-D space depiction” is denoted by the combination, or “junction,” of the three quantum numbers (n, l, and ml) described above; a common metaphor is an address for an orbital’s “volume probable.”     

“Useful tools are Q. N. rules, /
To name electrons’ ‘domiciles.’”
Quantum numbers and the rules describing them give us a succinct way to identify the “domicile” of an electron: the orbital in which it “resides.”  While such imagery is, of course, not nearly as precise as the mathematics used in advanced coursework to further explore atomic orbitals, this analogy provides an accessible and important step for students in understanding the concept.   

Categories
Science Poetry

Metric Systems

“Can metric prefix to a poem’s foot 
Be pre-appended?
In Shakespeare’s verse, do mega-iambs
Broaden sonnets splendid? 
In brief rhymes, nano-anapests?
No, queries such are censured,
Since feet are units English:
Closing lines’ response is measured.”

The 2 September 2019 Twitter poem involved a number of variations on the same idea, which was the contrast between two “metric systems”: one used in chemistry, with the prefixes that immediately communicate important information about scale; and the other used in English, to communicate information about poetic rhythms.  

Can metric prefix to a poem’s foot /
Be pre-appended?
The first two lines introduced the idea stated above, querying whether the two types of metric systems could be combined, to use STEM’s prefixes to modify English literature’s poetic feet.  

In Shakespeare’s verse, do mega-iambs
Broaden sonnets splendid? 
In brief rhymes, nano-anapests?
The next three lines explore two examples of this potential combination, based on the scope of the prefix of interest.  “Mega” is a metric prefix meaning a factor of one million (106); it makes a number six orders of magnitude larger.  Given the grandeur and fame of Shakespeare’s sonnets, written in iambic pentameter, the “mega” scale seems potentially fitting for these iambic feet (which consist of one unstressed syllable, then one stressed syllable).  “Nano” is a metric prefix meaning a factor of one-billionth (10-9): it makes a number nine orders of magnitude smaller and so could presumably make a brief rhyme quite a bit more fleeting!  The anapest foot consists of two unstressed syllables, then one stressed syllable.  (Samuel Taylor Coleridge has summarized the rhythms of these and many others in his “Metrical Feet.”)

No, queries such are censured,
Since feet are units English:
Closing lines’ response is measured.
The last three lines ruminate on the mismatchedness of these combinations with two puns.  First, feet are defined as “units English,” which has a double meaning, given both its literature-based uses above and the measurement unit’s heritage.  [Metric prefixes can only be used with metric units (e.g., “kilometer” is a valid use, since “kilo” is a metric prefix and “meter” is part of the metric system, but “kilofoot” would not be… and indeed, looks gratingly wrong!).]  Second, the poem characterizes its response as “measured”: a phrase implying deliberate rumination but also highlighting the metrology theme of this verse.     

Categories
Science Poetry

Wake-Up Calls

“The coffee brews; its volatility
Gives rise to the day’s volubility.  
This vital transaction
Of aqueous extraction 
Relies on caffeine’s solubility!”

The 6 August 2019 limerick discussed a theme fitting for early days of an academic year: the chemistry involved in making coffee.  

“The coffee brews; its volatility /
Gives rise to the day’s volubility.”  
Like many people, I rely on coffee in the morning.  Its aroma as it steams out of a mug–  a loose but ideally reasonable take on volatility, which in a chemical context involves the evaporation of a liquid to a gas– helps me prepare for the classes ahead, which require alertness and communicativeness, both inherent in volubility.  “Volatility” and “volubility” provide here an imperfect starting rhyme; the second line is essentially a set-up for the fifth.  

“This vital transaction /
Of aqueous extraction / 
Relies on caffeine’s solubility!”
Solid chemical compounds (in this context, solutes) can be soluble to different extents in different solvents: that is, they can dissolve more easily in some solvents than others.  Often, solutes are classified as aqueous-soluble (they dissolve in water) or organic-soluble (they dissolve in organic solvents). Differences in solubility can be exploited in the laboratory to separate mixtures of compounds, using a piece of glassware called a separatory funnel.  

As this poem suggests, principles of solubility can also be useful in the kitchen!  For someone who is far from alert when the alarm goes off, a routine of drinking coffee quickly becomes a “vital transaction,” each morning.  Brewing coffee involves pouring water over coffee grounds; because the caffeine in the coffee grounds is water-soluble, especially at high temperatures, it dissolves in the water and the resulting solution drips into the coffeepot.  Thus, this is an “aqueous extraction,” since the act of making coffee is reliant on caffeine’s solubility in water.  As alluded to above, the rhyme of “volubility” and “solubility” was the inspiration for this particular limerick.    

Categories
Science Poetry

D.C. al fine

1.
“Lunar photography’s 
Silvery filigree 
Celebrates odyssey set in the skies.
Elegant element’s
Photodevelopment:
Silver’s reduction enables moon’s rise.

2. 
Moments of alacrity,
Sagacity, tenacity—
STEM, sports, music, history—
Enveloped in philately.”  

This week’s entry expands on two Twitter poems that I wrote about my July 2019 trip to Washington, D.C., discussing two museums that I was fortunate to visit.  I’ll write both explanations in a single entry– discussing the trip from the beginning to the end, as it exists in this virtual space– so that I am justified in using “D.C. al fine” as the title.  

Lunar photography’s /
Silvery filigree /
Celebrates odyssey set in the skies.
The National Gallery of Art hosted an exhibit on lunar photography entitled “By the Light of the Silvery Moon” as part of the fiftieth anniversary of the Apollo 11 moon landing.  Many of the images were from black-and-white photography, a technique which relies on a chemical reaction involving a silver halide (AgCl, AgBr, or AgI).  “Silvery filigree” is thus a poetic way of describing such images, celebrating the sky-set “odyssey” from Earth to the moon.  

Elegant element’s /
Photodevelopment: /
Silver’s reduction enables moon’s rise.”
The latter lines of this poem directly discuss the chemistry involved with black-and-white photography.  Silver is the “elegant element” involved in the process; in the specific reaction of interest, a light-sensitive precipitate containing a positively charged silver ion is coated onto a surface.  When the surface is exposed to light, the silver ion in the precipitate is reduced to elemental silver.  

The last line celebrates the interesting contrast of mental images present in the chemical process and its artistic result.  The reduction of silver from a cation to a neutral atom is what allows the emergence of the image: here, the “moon’s rise.”      

***

Moments of alacrity, /
Sagacity, tenacity— /
STEM, sports, music, history— /
Enveloped in philately.”  
I was fortunate to live near Washington, D.C. during my postdoctoral work, and I traveled often into the city.  The National Postal Museum became one of my favorite places to visit: rarely crowded and always interesting.  It was fun to return during my 2019 vacation. 

This brief verse highlights the wide range of images on postal stamps: moments of celebration, contemplation, and dedication, across a wide range of fields.  The poem itself is quite simple: several variations on the central rhyme of “philately” (and an allusion to envelopes, for good measure).   

Categories
Science Poetry

Case Studies

“To calculate rate arithmetic
Of reaction, cite info kinetic.  
(Common error displayed: 
Writing capital K.
For rate constant, use lower-case metric!)” 

The 24 July 2019 limerick examined a particular piece of symbolic notation that often sees some misapplication in General Chemistry.   

To calculate rate arithmetic / 
Of reaction, cite info kinetic.”  
Questions of whether a chemical reaction will occur or not involve “spontaneity,” a term with a specific meaning in chemistry.  A reaction that is spontaneous is one that occurs naturally; “spontaneous,” as a descriptor in a chemical context, is unrelated to a reaction’s speed.  (This is a case of unhelpfully mismatched chemical and everyday definitions.) 

To communicate information about the rate of the reaction, we instead use kinetic data.  The rate constant, or rate coefficient, is one piece of this data.  It is represented by a lower-case k.  The rate law of a given reaction indicates how the reaction rate depends on the rate constant and on the concentrations of species involved in the reaction.   Determining a rate law from kinetic data is a common experimental goal.     

(Common error displayed: / 
Writing capital K. /
For rate constant, use lower-case metric!)” 
In chemistry, similar or identical symbols can be used in multiple settings with multiple meanings, a phenomenon that can be confusing.  (For instance, the capital letter H, in chemistry, can represent hydrogen, or enthalpy, or the Hamiltonian operator: each with a distinct conceptual meaning.) As learners progress from novices to experts, they become adept at reading the context clues. 

In General Chemistry coursework, students are typically introduced within the span of only a few weeks to two major topics: kinetics and equilibrium.  In the former, the lower-case k represents a rate coefficient.  In the latter, a capital K represents an equilibrium constant, a different quantity.   While the two types of constants are related to one another, it is common to see them simply used interchangeably in introductory assignments: this is an error displayed.”

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Science Poetry

Trend Analysis

“Celebrate, elevate
Sesquicentennial
Chart periodic, the chemist’s best friend.  
Innovate, explicate
Lessons perennial,
Elements ordered in table-set trends.”  

The  23 July 2019 Twitter poem was another entry for C&E News’s “Periodic Poetry” contest, highlighting the periodic table and that table’s central role for chemists.  As with the 8 July 2019 poem, this verse doesn’t fully meet the stringent standards of the double dactyl form (a.k.a. the “higgledy piggledy”), but it comes close.  

“Celebrate, elevate / 
Sesquicentennial /
Chart periodic, the chemist’s best friend.” 
The first three lines highlight the celebratory nature of the International Year of the Periodic Table, the 150th (sesquicentennial) anniversary of Dmitri Mendeleev’s 1869 initial publication.  The periodic table is an indispensable tool for chemists, presenting a wealth of important data in an organized way.  (As a sidenote, “sesquicentennial” is one of a set of terms uniquely suited for the higgledy-piggledy form, given that it is a double-dactylic word; seeing it in a list of such words provided this poem’s inspiration.)    

“Innovate, explicate / 
Lessons perennial, /
Elements ordered in table-set trends.” 
Each fall, when teaching the history and use of the periodic table, I review my lecture notes, add in new details and examples, and generally attempt to “innovate, explicate [my] lessons perennial.” 

Mendeleev ordered the elements according to their chemical and physical properties, resulting in a chart that can predict relative information about a wide number of behaviors.  For instance, sodium (Na) and potassium (K) are in the same column, or family, in the periodic table.  Because potassium is underneath sodium in their column, a chemist thus can quickly make predictions about their relative atomic size (more precisely called atomic radius); the relative energy required to remove an electron from either atom (called the first ionization energy), and many other properties.  Periodic trends are “table-set”: in many cases, a chemist can use the periodic table to predict the relative magnitudes of elements’ physical and chemical properties.  

It is intriguing to contrast another common meaning of “higgledy-piggledy”– chaotic and disordered— with both the strict rules for this poetic form and the highly organized chemical chart which this poem celebrates!           

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Science Poetry

Rotational Profiles

“Gauche interactions are 
Torsional infractions;
Likewise, groups eclipsing, so see option third…
Butane in profile
Rotates from erstwhile 
Higher-strain conformers: anti’s preferred.”

The 22 July 2019 Twitter poem examines a concept from organic chemistry, the energetic costs and benefits available to a molecule as it rotates through its conformations: specifically, the poem discusses the ways that the molecule butane can arrange itself in three-dimensional space.  This is a highly visual topic, so I’m intrigued to see what I can communicate in the 280 words below (with many links!).    

Gauche interactions are /
Torsional infractions; /
Likewise, groups eclipsing, so see option third…
The molecule butane (C4H10) consists of four carbon atoms in a line, covalently bonded.  Carbon atoms form four bonds, so butane’s terminal carbon atoms (first and last in line) each form three additional bonds to hydrogen atoms, while the middle two carbon atoms each form two additional bonds to hydrogen atoms.    

Rotation around butane’s central carbon-carbon bond leads to a variety of conformers.  Different conformers’ atoms interact with one another differently (their electron clouds repel, incurring energetic costs) through three-dimensional space.  Chemists have vocabulary to describe these torsional interactions: so named since interactions arise from the molecule’s torsion (twisting).    

The most intuitively named is the eclipsed conformer; if the methyl groups (the terminal carbon atoms, bonded to three hydrogen atoms apiece) are eclipsing, these groups line up with one another like the hands of a clock at noon. This is most easily seen through a chemistry model called a Newman projection.  Eclipsing incurs the highest possible energetic cost, or “torsional infraction,” in this molecule.  

Other energetic penalties arise in the gauche conformer, where the methyl groups are in something akin to a “2 p.m.” orientation. 

Butane in profile /
Rotates from erstwhile / 
Higher-strain conformers: anti’s preferred.
As portrayed in a rotational profile of butane, the anti conformer (an approximation of a clock’s “6 p.m.” orientation) keeps the methyl groups as far away from one another as possible and is the most energetically beneficial (“preferred”) conformation.  The anti conformer avoids torsional strain, although butane can still rotate into other conformations (“erstwhile higher-strain conformers”) as well.