In the Classroom
Puzzling through General Chemistry: A Light-Hearted Approach to Engaging Students with Chemistry Content
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Susan L. Boyd Department of Chemistry, Mount Saint Vincent University, Halifax, Nova Scotia, Canada, B3M 2J6;
[email protected] First-year general chemistry is often considered to be a dry course, particularly for students who are taking it as part of the requirements for majors other than chemistry itself. Numerous authors have used puzzles relating to the topics being taught to help to change this perception. Among these are many puzzles that are not meant for teaching or testing, but are simply fun and challenging (1). Also, many games (2, 3) and mysteries (4) involving chemistry have been developed. There are now several sites on the Internet for chemistry puzzles, games, and mysteries (5–7). Indeed, White completed a M.A. thesis investigating the role of computerbased puzzles in chemical education (8). This Journal has been a consistent source of excellent, humorous, teaching aids and puzzles for the past 80 years (9), and actively seeks contributions for its spring “April Amusements” feature. CHEM13 News has for years published puzzles, particularly those of Toogood (10). This paper introduces puzzles designed to be used by students as learning tools. Other authors have also followed this vein. Helser (11) developed a large number of clever wordsearch puzzles relating mainly to biochemical topics; he also created a metric matrix on the metric system (12). Russell reported in a poster presentation on word puzzles she has developed (13). There is a challenging spiral puzzle for organic students, designed to test the ability of students to remember named reactions (14). This paper and its Supplemental MaterialW add to the realm of puzzles that are meant to teach or reinforce chemical concepts. They include word and number puzzles based on material covered during the first semester of first-year general chemistry (List 1). The topics of the puzzles are based on the first 10 chapters of the text that we currently use in our general chemistry course: Chemistry: The Central Science,
by Brown, LeMay, and Bursten (15). The topics, however, are appropriate to accompany most texts at this level. One goal in creating these puzzles has been to use a variety of formats. Consequently, there are crossword puzzles (of a sort), wordsearches, number searches, puzzles based on definitions, ones involving calculations, and some focusing on reactions. Several have twists in the process of solving them that are intended to be light-hearted. Incorporating Puzzles in the Curriculum An example puzzle, “The Awesome Quantum”, which is based on the electronic structure of the atom, is included here as Table 1; Table 2 provides the solution. This puzzle involves electron configurations for atoms and ions and is based on the material in Chapters 6 and 7 of ref 15. Students are instructed that for each species description except the first one, they should supply the symbol for the species (atom or ion) described in each row, note the first letter of that symbol, and then combine the first letters of the symbols to make a statement. All the puzzles (with solutions) described in List 1 are available as Supplemental Material.W I assign these puzzles occasionally when I sense the need for a lighter approach to the material we have been covering. Their purpose has been to make the material more interesting while reinforcing some of the concepts taught in the classroom. In the past, I gave the puzzles as optional exercises, which some of the students really enjoyed but the majority chose not to do. Consequently, I now use one or two puzzles each term as assignments in lieu of one of the weekly quizzes, ten of which account for 10% of the course grade. A given puzzle therefore is worth only 1%. Because of this low value, I have not worried about the likelihood of cheating. In fact, the students working together in some cases has
List 1. Puzzle Topics Corresponding to the Course Textbook Chapters Textbook Chapters (see ref 15)
Titles of the Related Puzzles (Type of Puzzle)
Chapter 1.
Matter and Measurement
A Matter of Definitions (a chemical word scramble puzzle)
Chapter 2.
Atoms, Molecules, and Ions
Nuclear Arithmetic (a particle number and isotope puzzle)
Chapter 3.
Stoichiometry
Neither Created Nor Destroyed (a chemical “crossnumber” puzzle)
Chapter 4.
Aqueous Reactions
Metathetical Search (a chemical acrostic puzzle and poem)
Chapter 5.
Thermochemistry
In the Heat and the Light (a chemical wordsearch)
Chapter 5.
Thermochemistry
How Much Thermo Is in the Chemistry? (a chemical number search)
Chapter 6.
Electronic Structure of the Atom
The Awesome Quantum (a chemical symbols and statement puzzle)
Chapter 7.
Periodic Properties of the Elements
And the Winners Are (a chemical crossword puzzle)
Chapter 8.
Chemical Bonding
Ties That Bind (a chemical wordsearch)
Chapter 9.
Molecular Geometry, Bonding Theories
The Shape of Things To Come (a “determine the element” puzzle)
Chapter 10.
Gases
Gaseous Conundrums (a “Which gas am I?” puzzle and poem)
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In the Classroom
Table 1. Puzzle: The Awesome Quantum
Species Description
Symbol
This is one of only two letters that does not appear on the periodic chart. It is the second of the two, alphabetically. 2
1
First Letter
—
3
The most important actinide, this atom has an outer shell configuration of 7s 6d 5f . This species, a ⫹3 ion, is isoelectronic with Ne. This nonmetal has the most unpaired electrons in the second period. The ᎑2 ion of this element is isoelectronic with Xe. If this element were to form a ⫹6 ion, it would have 86 electrons. This neutral atom has an outer shell configuration of 3s 2 .
An excited state configuration for this neutral atom is 1s 2 2s12p3. This neutral atom is isoelectronic with H᎑ . This lanthanide has two, unpaired 4f electrons. This is the fifth period element with the most unpaired electrons.
This fifth period element has one p-electron. This is the smallest member of the oxygen family with a complete set of d-orbitals.
The neutral species has a ground state configuration of 1s 2 2s22p63s23p6. This seventh period element has outer shell configuation ns2(n⫺2)f14(n⫺1)d7. All d-orbitals of this fifth period element are full, but the s-orbital is only half-full. The ⫹2 ion of this element has configuration 1s 22s22p63s23p63d10. This atom has a valence shell of 5s 25p5. This second period element has all its s- and p-orbitals full. This fourth period element has a valence shell related to that of carbon. The statement formed by the first letters of the above elements or ions is: !
stimulated questioning, interest, and a bit of competition. The puzzles have therefore proved to be popular, a welcome variation from the regular routine, and a teaching approach that I will continue to use. My hope is that others will find them equally useful and entertaining. W
Supplemental Material
The entire set of puzzles described in List 1 and their solutions, as well as the answer to the puzzle in Table 1, are available in this issue of JCE Online. Literature Cited 1. A partial, categorized list. Cryptic crossword puzzles: (a) Harris, A. D. J. Chem. Educ. 1986, 63, 1055. Broadly based crossword puzzles: (b) Crawford, R. D. J. Chem. Educ. 1992, 69, 966; 1993, 70, 976–977. Crossword puzzles focused entirely on chemical terminology: (c) Sawrey, B. A. J. Chem. Educ. 1986, 63,
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1111; (d) Most, C. Jr. J. Chem. Educ. 1993, 70, 1039–1040. Anagrams based on the elements: (e) Thomas, N. C. J. Chem. Educ. 1992, 69, 984; (f ) Mattern, D. L. J. Chem. Educ. 1995, 72, 1092. Anagrams based on biochemical terminology: (g) Helser, T. L. J. Chem. Educ. 1993, 70, 1009. Other elemental plays on words: (h) Helser, T. L. J. Chem. Educ. 1986, 63, 1051. Matrix puzzles on elements: (i) Earl, B. L. J. Chem. Educ. 1991, 68, 1011; (j) Kelkar, V. D. J. Chem. Educ. 2002, 79, 456– 457; 2003, 80, 411–413. Puzzles in logic: (k) Castro-Acuòa, C. M.; Dominguez-Danache, R. E.; Kelter, P. B.; Grundman, J. J. Chem. Educ. 1999, 76, 496–498. 2. Review of chemistry-related board games: Russell, J. V. J. Chem. Educ. 1999, 76, 481–484. 3. A partial, categorized list of games suitable for groups or classes. Safety: (a) Gublo, K. I. J. Chem. Educ. 2003, 80, 425. Elements: (b) Tejada, S.; Palacios, J. J. Chem. Educ. 1995, 72, 1115–1116; (c) Koether, M. J. Chem. Educ. 2003, 80, 421–422. Nomenclature: (d) Crute, T. D. J. Chem. Educ.
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4. 5. 6. 7. 8.
2000, 77, 481–482. Functional groups: (e) Welsh, J. J. J. Chem. Educ. 2003, 80, 426–427. Product prediction: (f ) Russell, J. V. J. Chem. Educ. 1999, 76, 487–488. VSEPR theory: (g) Myers, S. A. J. Chem. Educ. 2003, 80, 423–424. General topics, game-show format: (h) Keck, M. V. J. Chem. Educ. 2000, 77, 483; (i) Campbell, S.; Muzyka, J. J. Chem. Educ. 2002, 79, 458. Waddell, T. G.; Rybolt, T. R. J. Chem. Educ. 2004, 81, 497– 501; see also references therein. Saunders, N. Creative Chemistry. http://www.creativechemistry.org.uk (accessed Jan 2007). Trimple, Tracy. The Science Spot: Puzzle Corner. http:// sciencespot.net/Pages/classpuzzle.html (accessed Jan 2007). Brooks, David W. Logic Puzzles for High School Chemistry. http://dwb.unl.edu/chemistry/puzzles/ (accessed Jan 2007). A Web-Based Course as a Tool for Chemical Education Research. Arneson, B. T.; White, J. A.; Lagowski, J. J. http:// www.utexas.edu/research/chemed/lagowski/brian_acs_orlando/ tool.htm (accessed Jan 2007). Originally this material was a
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9. 10. 11.
12. 13.
14. 15.
poster presentation at the 223rd National Meeting of the American Chemical Society, Orlando, FL, Apr 7–11, 2002; CHED-57. Howell, J. E. J. Chem. Educ. 1999, 76, 455. For example, see: Toogood, G. CHEM13 News 2004, 312, 4–5. Helser, T. L. J. Chem. Educ. 1994, 71, 1022; 1999, 76, 494; 1999, 76, 495; 2000, 77, 479; 2000, 77, 480; 2001, 78, 474; 2001, 78, 483; 2001, 78, 503; 2003, 80, 414–416; 2003, 80, 417–418; 2003, 80, 419–420; 2004, 81, 515–516; 2004, 81, 517–518; 2005, 82, 551–552; 2005, 82, 552. Helser, T. L. J. Chem. Educ. 1992, 69, 986. Russell, J. V. Abstracts, 214th National Meeting of the American Chemical Society, Las Vegas, NV, Sept 7–11, 1997; American Chemical Society: Washington, DC, 1997; CHED-021. Erdik, E. J. Chem. Educ. 2003, 80, 428–430. Brown, T. L.; LeMay, H. E., Jr; Bursten, B. E. Chemistry: The Central Science, 10th ed.; Prentice-Hall: Upper Saddle River, NJ, 2006.
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