Chemistry for Everyone
Letter Matrix Puzzle on the Symbols of Elements V. D. Kelkar Department of Chemistry, University of Pune, Pune 411 007, India;
[email protected] Puzzles and quizzes are usually useful as well as entertaining because they give knowledge along with fun. Their appropriate use can stimulate student interest and reinforce factual knowledge. A word-search puzzle related to the names of the first 103 elements, An Element Hunt, at the beginning of the chapter on the periodic table in ref 1, is a good example to illustrate these points. A 2 × 2-letter matrix puzzle related to the symbols of 10 elements (as a problem at the end of the chapter on atoms and elements) in ref 2 is another example. This article presents a 3 × 3-letter matrix puzzle based on the symbols of 35 elements. Letter Matrix Puzzle
(Ti and Zr), and (when mixed with 20% nitrogen) in gas-filled electric bulbs. 7 & 1. A metal alloyed with zirconium to make wires for superconducting magnets. 7 & 4. Isotope of this element having mass number 237 is converted by neutron irradiation to 238Pu, which is useful as a power source in satellites (3). 8 & 2. A platinum-group metal that has the highest density of any element, 22.61 g cm᎑3. 9 & 6. Hardest, densest, and one of the most costly of the rare earth elements. Its name is derived from the ancient name for Paris, Lutetia (4).
Vertical: downward
In this 3 × 3 matrix puzzle, the squares are numbered as shown. Below, clues are given to the identity of 35 elements. The symbols of these elements are to be written in the square or squares bearing the numbers shown in the clues, in the order specified, assigning only one letter to each square. Thus the twoletter symbols may appear vertically, horizontally, or diagonally in either direction. There is only one correct solution. 1
2
3
4
5
6
7
8
9
One-Letter Symbols: Single Squares 1. An element whose carbide is almost as hard as diamonds and is used in making abrasives and tools. 3. The nonmetallic element with the highest melting point. 4. An element whose symbol and name are derived from its Latin name applied to the planet Venus when appearing as a morning star. This element forms a range of trisubstituted ligands. 6. An element whose oxide is a black, insoluble, crystalline and radioactive substance. This dioxide is used as a fuel in advanced gas-cooled reactors. 7. Colorless, odorless, and tasteless gaseous nonmetal that comprises 78% by volume of air. 8. A blackish gray element that gives off a violet vapor. Its radioisotope has a half-life of 8.6 days and is used in the treatment and diagnosis of disorders of the thyroid gland.
2 & 5. The extremely scarce alkaline earth metal. It was first isolated by Pierre and Marie Curie by processing many tonnes of the uranium ore pitchblende. 3 & 6. An element whose accumulation in the body causes Wilson’s disease. 3 & 9. The commercially most important halogen.
Horizontal: forward 1 & 2. An element that is a brown liquid. 4 & 5. A radioactive metallic element belonging to the actinides (atomic number 91). Its name was adopted as being more consistent with the characteristics of its most abundant and long-lived isotope (having mass number 131), which is the parent of actinium and, like it, an alpha emitter. 4 & 6. All isotopes of this member of the actinide series are important as nuclear fuels. 5 & 6. The precious metal that is the most electronegative metal. 7 & 8. An element used in U.S. coins, for which one coin is named.
Horizontal: backward 2 & 1. An alkali metal (atomic number 37). Its spectrum revealed two dark red lines and therefore its name was derived from the Latin term rubidos meaning deepest red. 3 & 2. If this metal were not present in minute quantities, the rich, red ruby would look like a piece of colorless glass. 8 & 7. This element is the most corrosion-resistant material known. 9 & 8. Certain mental disorders are treated with the salts of this metal.
Two-Letter Symbols: Two Squares Vertical: upward
Diagonal: left to right, upward or downward
4 & 1. This toxic metal is very dense and has derived its symbol from its name in Latin, plumbum.
1 & 5. An element whose sulfate is used to image the digestive system because it is opaque to X-rays.
5 & 2. A noble gas (atomic number 18). Its uses include inert atmospheres in welding and special-metal manufacture
2 & 6. An element whose name is derived from the Latin name Ruthenia of the country Russia (4).
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Journal of Chemical Education • Vol. 79 No. 4 April 2002 • JChemEd.chem.wisc.edu
Chemistry for Everyone
Solution
7 & 5. The most abundant alkali metal.
9&2 Lr
2&7 Rn
1&8 Bi
9&5 La
3&5 Ca
5&3 Ac
4&2 Pr
2&6 Ru
1&5 Ba
9&8 Li
8&7 In
3&2 Cr
2&1 Rb
5&6 Au
4&6 Pu
4&5 Pa
1&2 Br
3&9 Cl
3&6 Cu
2&5 Ra
7&1 Nb 7&4 Np
5&2 Ar
4&1 Pb
3 & 5. An alkaline earth metal that gives a brick-red flame test.
6
5
C
R
B 1
U
A
P 2
8
I
9
8
4
L
I
N
3
1. Medeiros, R. W. Chemistry: A Modern Perspective; Van Nostrand: New York, 1973; Chapter 5, pp 73, 102. Reproduced from Chemistry with permission, © American Chemical Society. 2. Kotz, J. C.; Treichel, P. Jr. Chemistry & Chemical Reactivity; 3rd ed., international ed.; Saunders/Harcourt Brace: Orlando,
N
7
Literature Cited
7
U
6
P
9&6 Lu
9 & 2. This element has the electronic configuration [Rn] 5f14 6d1 7s2.
8&2 Ir
2 & 7. A member of the rare gases that is naturally occurring and radioactive.
4
7&8 Ni
1 & 8. A metal of group 15 or group VA that gives the nonradioactive natural isotope of the highest mass number.
C
7&5 Na
Semi-diagonal (Knight’s move in chess)
5&9 Al
9 & 5. Molybdenum and tungsten are similar in their properties because of a “contraction”.
3
Diagonal: right to left, upward or downward
B
5 & 3. The first 5f series element. 5 & 9. The element whose production is based on the Hall– Heroult process and this production is the largest electrochemical industry in the world.
FL, 1996; Chapter 2, pp 99 (problem 65), A-59 (solution). Original: Cyvin, S. J. Chem. Eng. News 1987, 65 (Dec 14), 86. ChemMatters 1988, 6 (Oct). 3. Lee, J. D. Concise Inorganic Chemistry, 4th ed.; ELBS with Chapman & Hall: London, 1991; pp 889, 896, 898. 4. Ball, D. W. J. Chem. Educ. 1985, 62, 787.
1
4 & 2. A soft silvery metallic element belonging to the lanthanides (atomic number 59). The M (III)-β-diketone complex in an organic solvent is used as a lanthanide shift reagent in NMR spectroscopy.
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