Teaching the Periodic Table and the International Phonetic Alphabet


Undergraduate students who take a phonetics course spend an awful lot of time learning the sounds associated with the various IPA [International Phonetics Alphabet] symbols.  There are transcription exercises and pronunciation exercises.  Students need to know, from the symbol, whether the sound is high or low, front or back, whether the lips are rounded or not, et cetera.  There are about 100 or so sounds to learn, and it takes quite a while.

Coincidentally, there are about 100 chemical elements in the periodic table.  Each element has a handful of properties that can be memorized (Iron melts at 1536C; Lithium is a metal that reacts with water; Ytterbium is a rare earth with 5 filled shells and a partial sixth shell of electrons), much like each sound in the IPA ([y] is a close-front rounded vowel; [a] is found in words like “stack”, “car”, “stock”, and “time”, depending on your variety of English; most stop consonants close the airway for about 100 milliseconds).

Both the IPA table and the Periodic Table are important parts of the vocabulary of their field.  You’ll have a hard time talking about speech if you cannot use the IPA, and you’ll have a hard time talking about chemistry if you don’t use the names of the elements.  Not impossible, because you can always describe a sound or an element by its properties, but discussions will be inconvenient and fraught with confusion.

There are differences, of course.   The big one is that the elements in the periodic table are really distinct, made so by nature.  You cannot get from Lithium to Sodium in 100 tiny steps.   Speech sounds, of course, are not really distinct.  Take most pairs of speech sounds and you can smoothly go from one to the other in tiny increments.  Speech sounds are really part of a continuum of sound and we divide them into categories, for our convenience, when we talk about them.  Mother Nature does not give us conveniently separated categories.

So, what does a chemist need to know about atoms vs. what a phonetician needs to know about speech sounds?

First, Chemists usually don’t need to recognize elements.  Elements either come in a bottle with a label, or you run some kind of test to find out what you have.  [About half of Chemistry is about making stuff and the other half is all about figuring out what some unknown stuff is.] Sure, maybe it’s occasionally useful to be able to say “funny, that doesn’t look like Tungsten”, but no sane chemist depends on his/her ability to recognize an element with bare eyes, nose, and tongue.

In contrast, undergraduate Phonetics students are expected to recognize sounds.  One of the standard parts of phonetics curricula, a part that’s been standard for almost a century, is the transcription exercise.  In it, a class hears a recording (or a live speaker) and writes down a sequence of phones that represent the sounds.  [Of course, recognizing sounds is rather safer and easier than the chemical equivalent, so an increased emphasis is sensible…]

Chemists aren’t expected to know much detail about many elements.  In GCSE Chemistry in Britain, today, students are expected to know basic properties of the first 20 elements.  First-year Phonetics students are supposed to learn somewhat more: basic properties of the sounds of their language, 40-50 sounds for a typical language, plus a few interesting ones from other languages.  Chemists are expected to learn the properties of rows or columns of the periodic table.   (E.g. “What do all alkali metals have in common?”)  Phoneticians have to know what all stops have in common, but the common properties are relatively few.

But a big difference is that most of the facts that chemists learn aren’t actually properties of elements so much as reactions that happen between two (or more) elements.  Lithium is taught (to a chemist) more by all the things it reacts with and what happens [Lithium reacts gently with water, but Caesium goes “Boom” when wetted] than by the properties of Lithium itself.  In contrast, basic Phonetics doesn’t pay attention to interactions between sounds, beyond a few facts like “a final /s/ is often realized as a [z] sound”.

The two fields have some similarities, but somehow the courses differ dramatically.   For instance, the University of Lausanne on-line Phonetics course [chosen somewhat at random from a Google search] is entirely descriptive.  It tells you where the tongue is for each sound, and what the spectrum looks like.   The course also tells you about the acoustics of the vocal tract, so you can understand how you get from one set of properties to the other.   The main headings are:

  1. Introduction
  2. The table of the phonetic alphabet
  3. Description of the Consonants
  4. Description of the Vowels
  5. Description of the Semi-Vowels
  6. Introduction to Acoustic Phonetics

Or, another Phonetics syllabus [University of Indiana, 1 term] covers the following.  It is less descriptive: items 5 and 6 deal with speech behaviors in the context of theory:

  1. to perceive and produce the most common sound types of the languages of the world, including Tone-and-Break Index (ToBI) transcription for English accents and intonation,
  2. the physiological properties of the speech-producing apparatus,
  3. the basic properties of sound in general,
  4. how speech sounds are similar and different from each other acoustically, including how to create and interpret acoustic displays using appropriate software,
  5. why speech performance is a challenging theoretical problem for (and possibly incompatible with) linguistic theory.
  6. how speech behavior reflects innate human predispositions plus lots of generalized learning.

For comparison, an online Chemistry course [MIT, 1 term] has the following headings.  The properties of one element is discussed in extreme detail (Hydrogen, lectures 5, 6), a group of elements in some detail (Transition Metals, 26), and everything else is covered as a “Multielectron Atom” (8).  Most elements are mentioned in terms of the reactions they are involved in, or it is assumed that the student can look up the relevant properties in the periodic table (lecture 9).  There is a lot of theory in there (3,4,7,10,13,17,18, 19,20,21,28,30,32, 33,34,35), and some quantitative information (18,19,21,22,23,24,31,34): students will be able to do some useful computations by the end of the class.

  1. The Importance of Chemical Principles
  2. Discovery of Electron and Nucleus
  3. Wave-Particle Duality of Light
  4. Wave-Particle Duality of Matter
  5. Hydrogen Atom Energy Levels
  6. Hydrogen Atom Wavefunctions
  7. P-Orbitals
  8. Multielectron Atoms and Electron Configurations
  9. Periodic Trends
  10. Covalent Bonds
  11. Lewis Structures
  12. Ionic Bonds
  13. Polar Covalent Bonds and VSEPR Theory
  14. Molecular Orbital Theory
  15. Valence Bond Theory and Hybridization
  16. Thermochemistry
  17. Entropy and Disorder
  18. Free Energy and Control of Spontaneity
  19. Chemical Equilibrium
  20. Le Chatelier’s Principle
  21. Acid-Base Equilibrium
  22. Chemical and Biological Buffers
  23. Acid-Base Titrations
  24. Balancing Redox Equations
  25. Electrochemical Cells
  26. Chemical and Biological Redox Reactions
  27. Transition Metals
  28. Crystal Field Theory
  29. Metals in Biology
  30. Magnetism and Spectrochemical Theory
  31. Rate Laws
  32. Nuclear Chemistry and Elementary Reactions
  33. Reaction Mechanism
  34. Temperature and Kinetics
  35. Enzyme Catalysis
  36. Biochemistry

Now, these courses are not strictly comparable, as all chemistry students at MIT can be assumed to have had some chemistry in secondary school, whereas undergraduate Phonetics students start essentially from zero.  But you see the same contrast between a descriptive, detail-based approach to Phonetics (even in more advanced Phonetics courses) vs. a big-picture, theory driven approach to Chemistry (even in secondary school courses).

The question is, how many sounds do students really need to be taught?