KOLAY SAĞLANABİLİR MALZEMELERLE MOLEKÜL MODEL YAPIMI

Kimyasal maddelerin kimyasal ve fiziksel özelliklerinin kavranabilmesi için, öncelikli olarak onların uzaysal yapılarının, yani moleküler geometrilerinin anlaşılması gerekmektedir. Halbuki, araştırmalar kimya öğretmeni adaylarının konu ile ilgili zorluklar yaşadıklarını göstermektedir. Bunun sebebi, moleküllerin duyu organları ile algılanamaz olmalarıdır. Üstelik, uzaysal yapıların hayal edilmesi, onların üç boyutlu yapılarının kâğıt düzlemine ve/veya tahta düzlemine çizilmesi başka bir zorluktur. Molekül gibi çok küçük yapıların modelleri yapılarak onlar görsel hâle getirilebilir. Bu çalışmada, merkezi atomunun hibrit tipi sp, sp2, sp3, dsp3, d2sp3, dp3 ve dsp2 olan bütün inorganik türlerin (moleküller, iyonlar, kompleksler) ve çok sayıda organik molekülün (alkinler, allenler, alkenler, alkanlar, sikloalkanlar, piranozlar, furanozlar, benzen) modellerinin ucuz ve kolaylıkla sağlanabilir malzemeler (karton kâğıt, oyun hamuru ve plastik başlı toplu iğne) ile yapılması için yöntemler verilmektedir. Ayrıca, molekül modellerinin içinde, öğrencilerin ve öğretmenlerin temel geometrik şekilleri anlamalarına yardımcı olacak geometrik şekil modellerine de yer verilmektedir.

Anahtar Kelimeler:

Kimya/fen/matematik eğitimi, modeller, molekül geometrisi, geometrik şekiller

MAKING THE MOLECULAR MODELS FROM EASILY OBTAINABLE MATERIALS

In order to comprehend the chemical and physical properties of chemical substances, firstly it is needed to understand their three–dimensional structures (that is, their molecular geometries). However, research literature shows that prospective chemistry teachers have difficulties related to the subject. The reason might be that molecules are entities not directly perceived by the sense organs. Moreover, to imagine the three–dimensional structures and draw the three–dimensional structures on paper or board plane, other difficulties are. By making the models of very small structures like molecules, they can be transformed a visual shape. In this study, in order to made the models of all inorganic species (molecules, ions, complexes) whose central atoms have the types “sp, sp2, sp3, dsp3, d2sp3, dp3 and dsp2” of the hybridisation and many organic molecules (alkynes, allenes, alkenes, alkanes, cycloalkanes, pyranoses, furanoses, benzene) by using cheap and easily obtainable materials (carton paper, play–dough and pin with plastic–head), the methods are explained. In addition, in order to help students’ and teachers’ understanding of the basic geometric concepts, it is given place also the geometric shape models in the molecular models.

Keywords:

Chemistry/science/mathematics education, models, molecular geometry, geometric shapes,

PDF

___

Atasoy, B. (1996). Atasoy Molekül Model Seti. Taşkent Cad. No 68/16, Bahçelievler, Ankara.
Ayas, A., Çepni, S., Johnson, D. ve Turgut, F. (1997). Kimya Öğretimi. Ankara: YÖK/Dünya Bankası Millî Eğitimi Geliştirme Projesi Hizmetöncesi Öğretmen Eğitimi.
Battino, R. (1983). Giant Atomic and Molecular Models And Other Lecture Demonstration Devices Designed for Concrete Operational Students. Journal of Chemical Education, 60(6), 485–487.
Bent, H.A. (1984). Uses (and abuses) of models in teaching chemistry. Journal of Chemical Education, 61(9), 774–777.
Cherif, A.A., Adams, G.E. and Cannon, C.E. (1997). Nonconventional Methods In Teaching Matter, Atoms, Molecules and The Periodic Table for Nonmajor Students. The American Biology Teacher, 59(7), 428–438.
Driel, J. van and Verloop, N. (1999). Teachers' knowledge of models and modelling in science. International Journal of Science Teaching, 21(11), 1141-1153.
Erduran, S. (2001). Philosophy of Chemistry: An Emerging Field with Implications for Chemistry Education. Science & Education, 10(6), 581–593.
Furio, C. and Calatayud, L. (1996). Difficulties with the Geometry and Polarity of Molecules–Beyond Misconceptions. Journal of Chemical Education, 73(1), 36–41.
Gillespie, R.J. (1963). The Valence–Shell Electron–Pair Repulsion (VSEPR) Theory of Directed Valency. Journal of Chemical Education, 40(6), 295–301.
Gillespie, R.J. (1970). The Electron–Pair Repulsion Model Molecular Geometry. Journal of Chemical Education, 47(1), 18–23.
Gillespie, R.J. (1974). A Defence of The Valence–Shell Electron–Pair Repulsion (VSEPR) Model. Journal of Chemical Education, 51(6), 367–370.
Gillespie, R.J. (1997). The Great Ideas of Chemistry. Journal of Chemical Education, 74(7), 862–864.
Gülçiçek, Ç., Bağcı, N. ve Moğol, S. (2003). Öğrencilerin Atom Yapısı-Güneş Sistemi Pedagojik Benzeştirme (Anoloji) Modelini Analiz Yeterlilikleri. Millî Eğitim Dergisi, 159, http://yayim.meb.gov.tr/dergiler/159/gulcicek-bagci- mogol.htm (25 Temmuz 2006).
Harrison, A.G. and Treagust, D.F. (1996). Secondary Students’ Mental Models of Atoms and Molecules: Implications for Teaching Chemistry. Science Education, 80(5), 509–534.
Harrison, A.G. and Treagust, D.F. (1998). Modelling In Science Lessons: Are There Better Ways to Learn with Models? School Science and Mathematics, 98(8), 420–429.
Hurwitz, C.L., Abegg, G., Garik, P. and Nasr, R. (2001). High School Students' Understanding of the Quantum Basis of Chemistry. Home Page of “The Quantum http://qsad.bu.edu/ed/ElementsofUnderstanding.pdf (11 Kasım 2003). Across Disciplines.”
Kuo, M–T., Jones, L.L., Pulos, S.M. and Hyslop, R.M. (2004). The Relationship of Molecular Representations, Complexity, and Orientation to the Difficulty of Stereochemistry Problems. The Chemical Educator, 9(5), 321–327.
Meyer, G.G. (2005). A Study of How Precursor Key Concepts for Organic Chemistry Success Are Understood By General Chemistry Students. Ph.D. dissertation. Kalamazoo, Michigan: Mallinson institute for Science Education, Western Michigan University.
Mortimer, C.E. (1979). Chemistry–A Conceptual Approach, 4th ed. New York: D. Van Nostrand Co.
Nakiboğlu, C. (2003). Instructional Misconceptions of Turkish Prospective Chemistry Teachers About Atomic Orbitals and Hybridization. Chemistry Education: Research and Practice, 4(2), 171–188.
National Research Council (1996). National Science Education Standards. Washington: National Academy Press.
Peterson, R.F. and Treagust, D.F. (1989). Grade–12 Students’ Misconceptions of Covalent Bonding and Structure. Journal of Chemical Education, 66(6), 459– 460.
Peterson, R.F., Treagust, D.F. and Garnett, P. (1989). Development and Application of A Iagnostic Instrument to Evaluate Grade–11 and –12 Students' Concepts of Covalent Bonding and Structure Following A Course of Instruction. Journal of Research in Science Teaching, 26(4), 301–314.
Purser, G.H. (1999). Lewis Structure Are Models for Predicting Molecular Structure, Not Electronic Structure. Journal of Chemical Education, 76(7), 1013–1018.
Sarıkaya, M. (1992). Pi Bağı Sayısı İle Lewis Yapısı, Hibritleşme Tipi, Hibrit Orbitallerinin Düzeni ve Molekül Şekli Arasındaki İlişki. G.Ü. Gazi Eğitim Fakültesi Dergisi, 8(4), 217–230.
Sarıkaya, M. (1995). A New Method for the Determination the Unsaturation Number and π–Bond Number. G.Ü. Gazi Eğitim Fakültesi Dergisi, 11(3), 165– 168.
Streitberger, H.E. (1994). Modelling molecules. The Science Teacher, 61(9), 46–48.
Tuckey, H., Selvaratnam, M. and Bradley, J. (1991). Identification and Rectification of Student Difficulties Concerning Three–Dimensional Structures, Rotation, and Reflection. Journal of Chemical Education, 68(6), 460–464.
Wu, H–K and Shah, P. (2004). Exploring Visuospatial Thinking In Chemistry Learning. Science Education, 88(5), 465–492.
Yılmaz, A. ve Morgil, İ. (2001). Üniversite Öğrencilerinin Kimyasal Bağlar Konusundaki Kavram Yanılgılarının Belirlenmesi. H.Ü. Eğitim Fakültesi Dergisi, 20, 172–178.