Volume 16, Issue 2  (2007)

Editorial:
D. Lazarov Test vs. Teacher Full text: PDF (137 K)	83
News:
Become a Friend	88
Letters to the Editor:
S.J. Hawkes Unsaturated Bonds Should Not Be Represented in Introductory Chemistry by Orbital Overlap	90
Curriculum Matters:
A. Tafrova-Grigorova, K. Yankulova, I. Baranovska Multimedia Modules: Chemical Bonds Full text: PDF (238 K)	92
Teaching Efficiency:
M. Minevska, J. Stefanova Comparison of the 'Life Skills' Strategy with PISA, Programme for International Student Assessment	99
Problems:
M. Palamareva, G. Pekov, D. Tasheva, P. Tsanova, H. Chanev Chemistry Entrance Exam (2006) in the Faculty of Chemistry of the University of Sofia	108
T. Baramov Stoichiometry: Problems on Solutions	134
Advanced Chemistry:
I. Kuleff About Polonium: The Killer of Secret Service Men	139
History and Philosophy of Chemistry:
A. Lamprou The Ethics of Synthetic Chemistry: Myths and Reality	149
Khimiya, Volume 16, Issue 2 (2007) Khimiya. 16, 83-0 (2007) Author(s): D. Lazarov: Abstract.The basic figure in school is the teacher. The teacher is responsible for the realization of the educational goals and the different learning/teaching methods combined with the new information-communication technologies are his/her tools in this direction. Undoubtedly the summative tests are proper instruments for an assessment of the pupils’ achievements. However they will be of use if their results are an object of careful discussion between the teacher and his/her students. The final responsibility for pupils’ assessment should belong to the teacher rather than to the machine. This assessment should have a complex character taking into account the overall teaching process in the school years rather than to emphasizing on incidental test records. top Khimiya. 16, 92-0 (2007) Author(s): A. Tafrova-Grigorova, K. Yankulova, I. Baranovska: Abstract.A Web-based multimedia product about chemical bonding has been developed. It consists of three components: Covalent Bond, Ionic Bond and Metallic Bond that are designed in similar manner: a tutorial section to support students learning with basic facts and information, and a test section to help learning the new concepts. Three-dimensional dynamic models and animated images visualize the formation of chemical bonds. The knowledge structure matches both the chemistry curricular contents of the foreign students’ preparatory course and the Bulgarian Secondary School. So the product can be used by these categories of students at school or at home. top Khimiya. 16, 99-0 (2007) Author(s): M. Minevska, J. Stefanova: Abstract.This paper compares the ‘Life Skills’ Strategy with PISA, the OECD Programme for International Student Assessment. The similarities and differences of both programs are exhibited. Recommendations for the application of these programs in our school practice are given. We place special emphasis upon ‘scientific literacy’ of the pupils because this literacy affects essentially the work of Chemistry teachers at school. top Khimiya. 16, 108-0 (2007) Author(s): M. Palamareva, G. Pekov, D. Tasheva, P. Tsanova, H. Chanev: Abstract.Two entrance exams were conducted in 2006 in the Faculty of Chemistry of the University of Sofia. Any of them included both a test with 20 questions and 4 problems. The present paper describes these tests and problems and explains the procedure of assessment of the prospective students. This paper would be beneficial for secondary school teachers and their pupils facilitating their training to successful entrance to the tertiary chemistry education. top Khimiya. 16, 134-0 (2007) Author(s): T. Baramov: Abstract.Some original stoichiometric problems are presented and the methods of their solving are described. The focus is on the preparation of solutions and their mixing – a usual practice in the teaching chemical laboratory; this practice, however, is found difficult by the fresh students. top Khimiya. 16, 139-0 (2007) Author(s): I. Kuleff: Abstract.In the present paper some information was given about generation, chemical properties of the element polonium, which was discovered by Pier and Maria Curie few years after discovering of the radioactivity by Henri Becquerel. In the paper some information about the content of polonium in the environmental materials and some kind of foods was given as well as some discussion about the radiation hazard by ingestion and inhalation of polonium-210 was presented. The hazard by smoking and accumulation of polonium-210 in human body was also discussed. top Khimiya. 16, 149-0 (2007) Author(s): A. Lamprou: Abstract.The products of chemical synthesis, it is claimed, “are new substances that change our material world for the benefit or harm of living beings” (Schummer, 2001). It is also claimed that chemists are to be held especially responsible, in comparison to other professionals, for their products (Schummer, 2001). But how different is synthetic chemistry from engineering or applied science so that one can justifiably speak of a difference in ethics? It has been claimed that the difference as regards ethics lies in the fact that for engineers the public welfare and safety are very important while for chemists public safety is not of special interest. Chemists are free to trade safety and welfare with other interests (Davis, 2002). I will argue that it is neither an easy decision nor an ethically neutral one to engage in such trade offs. It has also been claimed that one can distinguish between chemical synthesis as an end in itself and chemical synthesis for utilitarian ends (Schummer, 2001). I will argue that the dividing line between chemical synthesis as an end in itself and chemical synthesis for utilitarian ends is not always clear. My view is that synthetic chemistry does not differ radically from other disciplines, which implies that the ethical responsibilities of chemists do not differ radically from those of other scientists. top