2011 – International Year of Chemistry
The Alchemy in Ambix (1937-1956) – Illustrated Bibliography
Резюме. In the International Year of Chemistry 2011 the Society for the History of Alchemy and Chemistry (SHAC) celebrates its 65th anniversary. The Society was established under the name: „Society for the Study of Alchemy and Early Chemistry“. So the alchemy was a major topic for Ambix in the first decades of its existence. The present article contains the full bibliography of the papers, published in Ambix in the period 1937-1956. This is an illustrated bibliography – selected illustrations from the cited contributions are reproduced with improved quality in comparison with the typographic quality of the originals. The role of the learned socieies in science is emphasized. It is expected an inclusion of elements of history and philosophy of chemistry in science education curricula to stimulate the interest of students to science and to improve teaching efficiency.
Keywords: alchemy, Ambix, bibliography, illustrations, SHAC
B.V. ToshevВлезте в системата, за да прочетете пълната статия
2011 – International Year of Chemistry
History of the Union of Bulgarian Chemists. V. The Radical Change (1945-1949) – Selected Documents
Резюме. This article describes through appropriate documents the activity of the Union of Bulgarian Chemists during the years 1945 – 1949. In this period the monarchy in Bulgaria was abolished and the Peoples’ Republic of Bulgaria was established under the power of the Communist Party. This historic event causes radical changes in the Bulgarian society which affect the activities of the Bulgarian chemists as well. Several documents illustrating these events are presented.
Keywords: Union of the Bulgarian Chemists, history, annual congresses, communism
N. NaydenovВлезте в системата, за да прочетете пълната статия
2011 – International Year of Chemistry
Stereochemistry of Simple Compounds, Ions and Complexes of d-Elements and Some Complexes of f-Elements
Резюме. Тhe article provides an empirical classifi cation of structures of simple compounds, ions and complexes of d-elements and some complexes of f-elements
with different coordination numbers in respect to the central atom. Many typical examples of such structures are given. These examples are recommended to be used in teaching practice.
Keywords: chemical bond, molecular orbital theory, valence bond theory,
hybridization, Hund’s rule, Jahn-Teller effect
E. KirkovaВлезте в системата, за да прочетете пълната статия
Scientific Literacy: A key Goal of Science Education in Schools
Резюме. The term scientific literacy first appeared in the educational literature in the late 1950s. In recent decades a key goal of science education in the years of compulsory schooling is the development of scientifi c literacy. The increasing impact of science and technology on life of the planet induce the need of scientifically literate population. A brief review of the international experience is made in this article. The author’s intention is to enhance a debate among educators in order to reveal the complex of factors that influence the promotion of greater scientific literacy.
Keywords: scientific literacy, science teachers, science curriculum, science education
A. Tafrova-GrigorovaВлезте в системата, за да прочетете пълната статия
Scientific Literacy: Teachers’ and Students’ Opinions
Резюме. Undoubtedly the scientific literacy should be considered as an important element of science education in school. The article collects opinions both of teachers and prospective teachers about the meaning of scientific literacy,its forms and its importance. We try to establish through these opinions what kind of skills, mastered in school, are considered as useful for the future life and career and which of these skills can be considered as elements of the scientific literacy. We have not established any difference in the opinions expressed by teachers or by students.
Keywords: science education, scientific literacy, knowledge and skills
Y. Stefanova, M. Minevska, S. EvtimovaВлезте в системата, за да прочетете пълната статия
Science Teachers’ Beliefs about Scientific Literacy
Резюме. This paper presents the results of a survey of science teachers’ beliefs about development of scientific literacy. The instrument used is a questionnaire
consisting of 21 close and open ended questions divided in three modules: Sample survey data, Teachers’ perceptions about scientific literacy, Interests and Attitudes towards Scientific Literacy. 47 Bulgarian science teachers have taken
part in the survey and have stated their interpretations of the scientific literacy concept, and given their views on the factors that influence the development of scientific literacy. The analysis of the respondents’ responses reveals, on the whole that teachers are familiar with the nature of this concept and realize that the attainment of scientific literacy should be one of the main aims of science education. They argue that the science curriculum should be improved in a way to ensure more real life knowledge, experimental work and key competences, and thus to enhance greater scientific literacy of students. The survey data show that science teachers are interested in a variety of modern scientific topics like environmental protection, new materials, nanotechnologies, food and health, green chemistry etc. They are aware of the need to increase scientific literacy for their students as well as for themselves.
Keywords: scientific literacy, science teachers, questionnaire, science education
A. Tafrova-Grigorova, M. Kirova, E. BoiadjievaВлезте в системата, за да прочетете пълната статия
137: A Bohr’s Theory Prediction of the Upper Limit for the Number of Chemical Elements
Резюме. The semi-classical Bohr´s model, although it is an incomplete and old theory, is one of the first approximations to the one electron atom that students learn. In this paper an answer is given using this model to a question that can often arise in introductory chemistry or atomic physics courses when dealing with the subject of the periodical table, namely if there is an upper limit for the number of chemical elements. It is hoped that the manuscript could be useful to teachers and students to learn about this question since the very first physics and chemistry courses.
Keywords: periodic table, Bohr’s model, atom, chemical elements
E. MarinВлезте в системата, за да прочетете пълната статия
Chemistry & History of Chemistry: An Online Supplement
A Reliable Simple Method for Prediction of the Flash Points of Saturated Hydrocarbons in Order to Improve Their Safety
Резюме. A reliable simple method is presented for predicting the flash point of pure cyclic and acyclic saturated hydrocarbons. The novel model is based on the number of carbon atoms as well as two structural parameters for improvement of the predicted results. The predicted flash points for a data set of 120 linear and branched alkanes as well as 59 cyclic alkanes are in good agreement with the measured values such that the root mean square (rms) error and the average absolute deviation are 4.6 and 5.4 K, respectively. The reliability of the new model for further 15 acyclic alkanes is comparable with several new models, which have been recently developed for acyclic alkanes. For 76 cyclic and acyclic alkanes, where outputs of complex method of neural network-group contribution method were available, the proposed model also provides good predictions. The proposed method can easily be used for different hydrocarbons including cyclic and acyclic compounds with complex molecular structures.
Keywords: flash point, saturated hydrocarbon, correlation, safety
M.H. Keshavarz, H. Motamedoshariati, M. GhanbarzadehВлезте в системата, за да прочетете пълната статия