Building a periodic table

Building the Periodic Table. The code letters A to Z have been assigned to the first 26 elements in the Periodic Table. Thev do not correlate in anv w...

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Building a Periodic Table Linda S. Fowler' Research Chemist Formica Corporation. R & D 8535 Brent Drive Cincinnati. OH 45231

"I've never had so much fun taking a test. That was great." "That lady must be crazy-that was impossible."

icity. No one is nonkm&ital. Students either enjoy it-and usually do well, or they dislike it and correspondingly have

..Students who were in my classes generally had little expea the students rerience utilizing reasoning skills. ~ s whole: sponded reasonably well to problems and situations which had

been specifically explained, but when a new problem was described, they tended to withdraw and wait for guidance. The exercise I will describe in this article2 was developed to help my students apply the knowledge they hopefully had previously learned to a new set of circumstances. T o carry out the exercise of constructing a periodic table, students were required to learn some problem-solving techniques and analytical skills. Thus, as the individual learned how to solve a specific problem, shelhe also acquired a methodology that could he applied to other kinds of tasks. Learning new abilities, such as ordering, coordination, and correlation of two systems of reference are very important when one is faced with a new situation where no present terhniaues are available for the nrohlem solver. After devel~- - ~ - ~ oping some basic problem-solving abilities, an individual will be able to deal more effectively with new challenges and new

Building the Periodic Table

The code letters A to Z have been assigned to the first 26 elements in the Periodic Table. Thev do not correlate in anv way with the real

Table A and fill in the correct atomic number for each in Table B. HINT!!! First find out in which vertical column each family of elements belongs, then arrange the elements within the groups

Table A

Clues 1) The following elements helong together in families: BFT-

DGLZ-.JNV-CMS-QXY-AEO-IPHUKWR 2) 31 4) 5) 6) I) 8) 9) 10) 11) 12) 13) 14) 15) 16) 17) 18) 19) 20) 21) 22) 23) 24)

Table B

25) 26) 27) 2s)

Atomic

29)

The oxidation states of H are 1 4 and -4. PC7 is the formula of an oxide. G i6 a noble gas. U is an alkali metal. E has 5 electrons in its outer shell. N is an alkaline earth metal. T has an electronic mnfiguration of 4s24p1 Q is a halogen. F has the smallest atomic mass in its family. T forms a stronger bane than B. The sulfate of V is more soluble than that of J but less than that of K. P has the lowest first ionization energy in its family. I is the second most abundant element but is not found free in nature. S's atomic radius is greater than that of C. C is more closely related to S than to M. Y is a liquid, whereas 4 is a gas a t room temperature X boils a t a lower temperature than 4. The salt UQ is less stable than KQ. The density of R is 0.53 glml and that of U is 0.91 glml. W is a gas. Atom Z has two neutrons. D contains ten protons. The electrons of atom G are distributed over three energy . levels. L has the highest critical temperature in its family. H is the least metallic element in its group. The electrons of atom 0 are distributed over three energy levels. 0 has a higher boiling temperature than does E. A is more metallic than either O or E. ~

634

Journal of Chemical Education

problems. Activities which encourage the use o f problemsolvine techniaues enhance the ahilitv of the students to think creatively. I n order t o comvlete the Periodic Table B u i l d i n g exercise. R s t u d ~ n tmust have an undrrstanding of p r r i d ~ trends r and Ile al)lc to reason abstractlv m d e f i n e d h .v Pisre!. t C'or a hrief . overview of Piaget's Theory o f Cognitive Development, see below.):' For the students who understand the chemistry and can think formally, this exercise is a reinforcing one. T h e other students may need varying degrees of assistance and w i l l benefit from being led through the mental manipulations required to build this periodic table. H i n t s can be given which break down the exercises i n t o smaller steps. T h e author has used this puzzle as a test. it can also be used h v small .groUDS o f 3 t o 5. T h e students could h e l n each other formulating the results. T h i s latter method applies another facet o f Piaeet's 'l'heorv o f C o m i t i v e I~evelovment-that of interaction w i t h peers. Another use of this exercise could he

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The author has taught chemistry on the high school and community college level for several years before accepting her present position in industry. The idea for this fable came from a pamphlet the author read years ago. The pamphlet has long since disappeared, but the author. whomever shelhe mav be. is acknowledoed. ~evel&ment describes sfaass of Piaoet's Thearv, df cdanitive -~ ~-~~ nte lect~aldeve opment. A staqc of oeuelopment is characterma by common aspects of actwties and reasonmq The last two stages. as described by Piaget, definethe mental abilities of most high school and college students. Logical reasoning begins in the concrete stage of development. Classifyingand use of symbols become evident. The last stage, one of abstract reasoning, describes fwmal thought wherein the individual can reason about objects which cannot be seen or experienced concretely. A person develops from thinking of actuality to possibility. A complete description of Piaqet's Theory of Cognitive Development can be found in the references. ~D~

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as a method o f evoking class participation, in the organization uf a large. seemingly confused body o f chemical knowledge. Care, however, is needed when grades are involved. since completion of this exercise requires dual emphasis. For details o n how this has been handled successfully in the classroom, please contact the author.

References Fouler. I.. S.. "An

Applicntim of Pinyet's Theow of(!oynitive

Dsvelupmenf in 'l'enrhins:

Chemlrtry: The 1.enrningCycle." J C b r m Bdu r... 67 lab. (19Ml). Purth. H. 1:.. and Wnrh.. H.. "Thinkina G a e h Srh