Abstract The early history of experiments in which an inflammable air was prepared is outlined. Once hydrogen had been discovered by Cavendish in 1766, the world of science and technology was given a colossal impetus. Its scientific and social consequences form the main focus of this essay. Special attention is given to explain why experiments were done, and their aims. The many difficulties which confronted scientists in the interpretation of their results are discussed. Timelines have been used in order to facilitate an understanding of the evolution of ideas. A particular emphasis is given to the story of how, through spectral analysis of the hydrogen atom, our understanding of atomic structure developed. Experiments involving hydrogen constitute important teaching material in schools. Detailed instructions are given for making hydrogen in the laboratory and for demonstrating its lightness and flammability. Suggestions are made of how to use these reactions to teach a wide variety of chemical concepts and facts.
{"title":"Hydrogen - Some Historical Highlights","authors":"Z. Szydło","doi":"10.2478/cdem-2020-0001","DOIUrl":"https://doi.org/10.2478/cdem-2020-0001","url":null,"abstract":"Abstract The early history of experiments in which an inflammable air was prepared is outlined. Once hydrogen had been discovered by Cavendish in 1766, the world of science and technology was given a colossal impetus. Its scientific and social consequences form the main focus of this essay. Special attention is given to explain why experiments were done, and their aims. The many difficulties which confronted scientists in the interpretation of their results are discussed. Timelines have been used in order to facilitate an understanding of the evolution of ideas. A particular emphasis is given to the story of how, through spectral analysis of the hydrogen atom, our understanding of atomic structure developed. Experiments involving hydrogen constitute important teaching material in schools. Detailed instructions are given for making hydrogen in the laboratory and for demonstrating its lightness and flammability. Suggestions are made of how to use these reactions to teach a wide variety of chemical concepts and facts.","PeriodicalId":41079,"journal":{"name":"Chemistry-Didactics-Ecology-Metrology","volume":"25 1","pages":"5 - 34"},"PeriodicalIF":0.4,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42959335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Kolář, R. Doležal, N. Karaskova, N. Maltsevskaya, Sarka Krizkova
Abstract Molecular models derived from results of quantum-chemical calculations present an important category of didactic instruments in chemistry education in upper secondary school and, particularly, at university. These models can be used especially as tools for supporting the students’ understanding by visual learning, which can adequately address complexity of many chemical topics, incorporate appropriate didactic principles, as well as utilize the benefits brought up by the actual information technology. The proposed molecular models are non-trivial examples of didactic application of computational chemistry techniques in illustration of electron interactions in amidic group, namely the interaction of the free electron pair on the nitrogen atom with the carbonyl group and also the interaction of atoms in the amide group with other surrounding atoms in the molecule. By these molecular models it is possible to explain acid-base properties of amides applying knowledge of electron density distribution in the molecules and the resulting electrostatic potential. Presentation of the structure and properties of the amides within education is important also for the reason that amidic functions are involved in many important natural substances (e.g. proteins, peptides, nucleic acids or alkaloids), synthetic macromolecular substances (e.g. Silon) or pharmaceutical preparations (e.g. paracetamol). Molecular models then serve to support better understanding of the structure of these substances and, in relation to it, their properties.
{"title":"Molecular Models in Chemistry Education at University and Upper Secondary School - Structure of Amides","authors":"K. Kolář, R. Doležal, N. Karaskova, N. Maltsevskaya, Sarka Krizkova","doi":"10.2478/cdem-2019-0003","DOIUrl":"https://doi.org/10.2478/cdem-2019-0003","url":null,"abstract":"Abstract Molecular models derived from results of quantum-chemical calculations present an important category of didactic instruments in chemistry education in upper secondary school and, particularly, at university. These models can be used especially as tools for supporting the students’ understanding by visual learning, which can adequately address complexity of many chemical topics, incorporate appropriate didactic principles, as well as utilize the benefits brought up by the actual information technology. The proposed molecular models are non-trivial examples of didactic application of computational chemistry techniques in illustration of electron interactions in amidic group, namely the interaction of the free electron pair on the nitrogen atom with the carbonyl group and also the interaction of atoms in the amide group with other surrounding atoms in the molecule. By these molecular models it is possible to explain acid-base properties of amides applying knowledge of electron density distribution in the molecules and the resulting electrostatic potential. Presentation of the structure and properties of the amides within education is important also for the reason that amidic functions are involved in many important natural substances (e.g. proteins, peptides, nucleic acids or alkaloids), synthetic macromolecular substances (e.g. Silon) or pharmaceutical preparations (e.g. paracetamol). Molecular models then serve to support better understanding of the structure of these substances and, in relation to it, their properties.","PeriodicalId":41079,"journal":{"name":"Chemistry-Didactics-Ecology-Metrology","volume":"24 1","pages":"45 - 51"},"PeriodicalIF":0.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46154849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The aim of the carried out research was to assess atmospheric aerosol pollution levels in the area of three apiaries located in the Opole Province and to analyse heavy metals pollution in bee honey and western honey bees. Pleurozium schreberi moss was used in analysing atmospheric aerosol pollution with the active biomonitoring method, whereas heavy metals levels were determined with flame atomic absorption spectrometry method (F-AAS). Relative Accumulation Factors (RAF) were used in determining increases of analytes concentrations in the moss samples. As a result of the carried out study, the following conclusions have been reached: mosses are good bioindicators of environment pollution thanks to their sorption qualities, similarly to honey bees, which are a bioindicator of environment pollution. According to the Commission Regulation of European Union of 2015 regarding the maximum levels of lead in certain foods (honey), it should not exceed 0.1 mg/kg. On the basis of the carried out study it can be stated that the concentration of this analyte in the analysed honey was below the limit of quantification of the applied analytical method.
{"title":"Biomonitoring of Atmospheric Aerosol with the use of Apis mellifera and Pleurozium schreberi","authors":"Z. Konopka, P. Świsłowski, M. Rajfur","doi":"10.2478/cdem-2019-0009","DOIUrl":"https://doi.org/10.2478/cdem-2019-0009","url":null,"abstract":"Abstract The aim of the carried out research was to assess atmospheric aerosol pollution levels in the area of three apiaries located in the Opole Province and to analyse heavy metals pollution in bee honey and western honey bees. Pleurozium schreberi moss was used in analysing atmospheric aerosol pollution with the active biomonitoring method, whereas heavy metals levels were determined with flame atomic absorption spectrometry method (F-AAS). Relative Accumulation Factors (RAF) were used in determining increases of analytes concentrations in the moss samples. As a result of the carried out study, the following conclusions have been reached: mosses are good bioindicators of environment pollution thanks to their sorption qualities, similarly to honey bees, which are a bioindicator of environment pollution. According to the Commission Regulation of European Union of 2015 regarding the maximum levels of lead in certain foods (honey), it should not exceed 0.1 mg/kg. On the basis of the carried out study it can be stated that the concentration of this analyte in the analysed honey was below the limit of quantification of the applied analytical method.","PeriodicalId":41079,"journal":{"name":"Chemistry-Didactics-Ecology-Metrology","volume":"24 1","pages":"107 - 116"},"PeriodicalIF":0.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43637851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Adsorption is an effective wastewater treatment technique which has been widely used in various industrial applications. However, the high operation cost involving commercial activated carbon in industrial processes is the main drawback. Sewage sludge is an auspicious precursor of activated carbon owing to its high carbon content, rich functional groups, low cost, high availability and abundance. This research was aimed to establish the feasibility of converting yarn processing sludge into activated carbon by KI + KOH activation and char at 700 °C for 1 h. The effect of preparation strategies on the properties of sludge-based adsorbents (SBA) was reviewed. The applications of SBAs in the removal of dyes and model pollutants were discussed. The results from this study proved that the preparation of yarn processing sludge-based activated carbon via KI + KOH activation is feasible and effective in the adsorption of dye. This paper provides further insight on the preparation methods of sludge-based adsorbents and dye wastewater treatment using these adsorbents.
{"title":"Isotherm Studies of Malachite Green Removal by Yarn Processing Sludge-Based Activated Carbon","authors":"S. Tang, M. Zaini","doi":"10.2478/cdem-2019-0011","DOIUrl":"https://doi.org/10.2478/cdem-2019-0011","url":null,"abstract":"Abstract Adsorption is an effective wastewater treatment technique which has been widely used in various industrial applications. However, the high operation cost involving commercial activated carbon in industrial processes is the main drawback. Sewage sludge is an auspicious precursor of activated carbon owing to its high carbon content, rich functional groups, low cost, high availability and abundance. This research was aimed to establish the feasibility of converting yarn processing sludge into activated carbon by KI + KOH activation and char at 700 °C for 1 h. The effect of preparation strategies on the properties of sludge-based adsorbents (SBA) was reviewed. The applications of SBAs in the removal of dyes and model pollutants were discussed. The results from this study proved that the preparation of yarn processing sludge-based activated carbon via KI + KOH activation is feasible and effective in the adsorption of dye. This paper provides further insight on the preparation methods of sludge-based adsorbents and dye wastewater treatment using these adsorbents.","PeriodicalId":41079,"journal":{"name":"Chemistry-Didactics-Ecology-Metrology","volume":"24 1","pages":"127 - 134"},"PeriodicalIF":0.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48910426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The history of fire is an important and fascinating topic, yet it is not covered in any school or university syllabus. In the present article, the author argues a case for its inclusion in chemistry teaching programs. He outlines some key points relating to investigations on the nature of combustion processes and the discovery of oxygen. Details are included for a class experiment with gunpowder, which is suitable for school pupils aged 13 to 15.
{"title":"History of Fire","authors":"Z. Szydło","doi":"10.2478/cdem-2019-0002","DOIUrl":"https://doi.org/10.2478/cdem-2019-0002","url":null,"abstract":"Abstract The history of fire is an important and fascinating topic, yet it is not covered in any school or university syllabus. In the present article, the author argues a case for its inclusion in chemistry teaching programs. He outlines some key points relating to investigations on the nature of combustion processes and the discovery of oxygen. Details are included for a class experiment with gunpowder, which is suitable for school pupils aged 13 to 15.","PeriodicalId":41079,"journal":{"name":"Chemistry-Didactics-Ecology-Metrology","volume":"24 1","pages":"23 - 43"},"PeriodicalIF":0.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47121578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Science teachers communicate curricula goals to their students, prepare teaching situations and lead their students through them in order to learn science. The purpose of this study was to identify the beliefs of teachers about teaching and learning, specifically, what the teachers focus on, how they comprehend knowledge and their role in the process of learning since they can promote or hold back development of scientific literacy. Q methodology was used to investigate the beliefs of 65 science teachers by having them rank and sort a series of 51 statements. Factor analysis was used to identify identical patterns. The analysis showed that the teachers held four types of dominant beliefs about the effectiveness of science instruction and some common feature which have potential to influence educational process. Teachers concentrate on covering the content even if they declare the importance of personal construction, feel responsible for students’ learning and its outcomes. Despite stressing the activity of the students, the teachers did not emphasize particular science process skills and scaffolding process. The findings of the study suggest that systematic trainings focused on the nature of science and the scaffolding process would be beneficial for teachers in all identified factors.
{"title":"Importance of Teachers’ Beliefs in Development of Scientific Literacy","authors":"Katarína Kotuľáková","doi":"10.2478/cdem-2019-0006","DOIUrl":"https://doi.org/10.2478/cdem-2019-0006","url":null,"abstract":"Abstract Science teachers communicate curricula goals to their students, prepare teaching situations and lead their students through them in order to learn science. The purpose of this study was to identify the beliefs of teachers about teaching and learning, specifically, what the teachers focus on, how they comprehend knowledge and their role in the process of learning since they can promote or hold back development of scientific literacy. Q methodology was used to investigate the beliefs of 65 science teachers by having them rank and sort a series of 51 statements. Factor analysis was used to identify identical patterns. The analysis showed that the teachers held four types of dominant beliefs about the effectiveness of science instruction and some common feature which have potential to influence educational process. Teachers concentrate on covering the content even if they declare the importance of personal construction, feel responsible for students’ learning and its outcomes. Despite stressing the activity of the students, the teachers did not emphasize particular science process skills and scaffolding process. The findings of the study suggest that systematic trainings focused on the nature of science and the scaffolding process would be beneficial for teachers in all identified factors.","PeriodicalId":41079,"journal":{"name":"Chemistry-Didactics-Ecology-Metrology","volume":"24 1","pages":"77 - 87"},"PeriodicalIF":0.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46744916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The present manuscript presents the view point of the author for providing a course on environmental history for chemistry students and secondary school pupils. Special attention is paid on the societal developments in the twentieth century when the anthropogenic impacts on the environment have become especially deep and devastating. The course of lectures is focused on the environmental changes in each environmental phase (lithosphere, atmosphere, hydrosphere, biosphere) as well as in the society as a whole. The process of environmental changes is illustrated by various examples from each natural system in consideration and the anthropogenic factor for each one of them is defined and discussed. The presented material is an example for organization of an environmental history course of lecture which could be subject of additional information and conclusions related to the social attitude to the problem of environmental pollution and environmental risk assessment.
{"title":"Environmental History of the Twentieth Century. An Introductory Didactic Course","authors":"V. Simeonov","doi":"10.2478/cdem-2019-0001","DOIUrl":"https://doi.org/10.2478/cdem-2019-0001","url":null,"abstract":"Abstract The present manuscript presents the view point of the author for providing a course on environmental history for chemistry students and secondary school pupils. Special attention is paid on the societal developments in the twentieth century when the anthropogenic impacts on the environment have become especially deep and devastating. The course of lectures is focused on the environmental changes in each environmental phase (lithosphere, atmosphere, hydrosphere, biosphere) as well as in the society as a whole. The process of environmental changes is illustrated by various examples from each natural system in consideration and the anthropogenic factor for each one of them is defined and discussed. The presented material is an example for organization of an environmental history course of lecture which could be subject of additional information and conclusions related to the social attitude to the problem of environmental pollution and environmental risk assessment.","PeriodicalId":41079,"journal":{"name":"Chemistry-Didactics-Ecology-Metrology","volume":"24 1","pages":"21 - 7"},"PeriodicalIF":0.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48875211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Karaskova, R. Doležal, N. Maltsevskaya, K. Kolář
Abstract This article presents the results of analysis of Czech and Russian textbooks intended for organic chemistry teaching at upper secondary schools. In principle, the estimation of textbook didactic capacity is based on decomposition of the textbook content into a set of different objects and their subsequent frequency analysis. In this study, three Czech textbooks and three Russian textbooks were characterized by particular and total didactic capacity coefficients. The indifference of the calculated didactic capacities was tested by chi-square statistics at a level of significance α = 0.05. The results show that the selected Czech and Russian textbooks are not significantly different.
{"title":"Didactic Capacity of Selected Czech and Russian Organic Chemistry Textbooks","authors":"N. Karaskova, R. Doležal, N. Maltsevskaya, K. Kolář","doi":"10.2478/cdem-2019-0005","DOIUrl":"https://doi.org/10.2478/cdem-2019-0005","url":null,"abstract":"Abstract This article presents the results of analysis of Czech and Russian textbooks intended for organic chemistry teaching at upper secondary schools. In principle, the estimation of textbook didactic capacity is based on decomposition of the textbook content into a set of different objects and their subsequent frequency analysis. In this study, three Czech textbooks and three Russian textbooks were characterized by particular and total didactic capacity coefficients. The indifference of the calculated didactic capacities was tested by chi-square statistics at a level of significance α = 0.05. The results show that the selected Czech and Russian textbooks are not significantly different.","PeriodicalId":41079,"journal":{"name":"Chemistry-Didactics-Ecology-Metrology","volume":"24 1","pages":"61 - 76"},"PeriodicalIF":0.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44709272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Environmental monitoring is a very important part of all environmental risk assessment tasks aiming correct estimation of the ecological status of water, air, soil, and biota systems. However, special attention is rarely paid to the problem in the teaching programs for students of bachelor or master degree dedicated to environmental chemistry. The same holds true for secondary school programs for chemical education. It is the aim of the present communication to present in a simple and understandable way the major elements of the environmental monitoring as substantial consistent of the overall scheme of environmental risk assessment as presented to chemistry students and secondary school pupils.
{"title":"Didactical Principles of Environmental Monitoring","authors":"V. Simeonov","doi":"10.2478/cdem-2019-0008","DOIUrl":"https://doi.org/10.2478/cdem-2019-0008","url":null,"abstract":"Abstract Environmental monitoring is a very important part of all environmental risk assessment tasks aiming correct estimation of the ecological status of water, air, soil, and biota systems. However, special attention is rarely paid to the problem in the teaching programs for students of bachelor or master degree dedicated to environmental chemistry. The same holds true for secondary school programs for chemical education. It is the aim of the present communication to present in a simple and understandable way the major elements of the environmental monitoring as substantial consistent of the overall scheme of environmental risk assessment as presented to chemistry students and secondary school pupils.","PeriodicalId":41079,"journal":{"name":"Chemistry-Didactics-Ecology-Metrology","volume":"24 1","pages":"106 - 99"},"PeriodicalIF":0.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45918167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The main reason of children’s low interest in the study of natural science subjects is the inability to link the knowledge acquired at school to subjects such as chemistry or physics with real life outside the classroom. Their ideas about the scientists are often mistaken and glamorized. With the effort of the Vebor camp, these ideas are corrected and shifted towards reality. The research was focused on the perception of children of selected concepts before and after the camp. There are many researches fields dealing with science camps or teaching outside of school. Our research has used the semantic differential method, which we have seen only sporadically in research on this subject. The results of the research are mostly positive and show that the scientific camp has a positive impact on the understanding and perception of children of selected aids from the area of science and education. Very interesting are the results, for example, when the term of “teacher”, where the connotative perception of the term has changed from very negative to highly positive with statistical significance of 99 %. Many of the more interesting results are presented in the article.
{"title":"Changes in Connotative Perception of Notions from the Area of Science Education at a Science Camp","authors":"Petra Ivánková","doi":"10.2478/cdem-2019-0004","DOIUrl":"https://doi.org/10.2478/cdem-2019-0004","url":null,"abstract":"Abstract The main reason of children’s low interest in the study of natural science subjects is the inability to link the knowledge acquired at school to subjects such as chemistry or physics with real life outside the classroom. Their ideas about the scientists are often mistaken and glamorized. With the effort of the Vebor camp, these ideas are corrected and shifted towards reality. The research was focused on the perception of children of selected concepts before and after the camp. There are many researches fields dealing with science camps or teaching outside of school. Our research has used the semantic differential method, which we have seen only sporadically in research on this subject. The results of the research are mostly positive and show that the scientific camp has a positive impact on the understanding and perception of children of selected aids from the area of science and education. Very interesting are the results, for example, when the term of “teacher”, where the connotative perception of the term has changed from very negative to highly positive with statistical significance of 99 %. Many of the more interesting results are presented in the article.","PeriodicalId":41079,"journal":{"name":"Chemistry-Didactics-Ecology-Metrology","volume":"24 1","pages":"53 - 60"},"PeriodicalIF":0.4,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43136775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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