The problematics of the teaching and learning of chemical bonding has been widely reported in the literature. Following this, Taber (2001) proposed a teaching sequence alternative to those available in existing curriculum documents and textbooks. He proposed that teaching be started from metallic structure to ionic structure, then giant covalent structure and finally simple molecular structure. During teaching, teachers should be cautioned about the use of language, the undue emphasis on the role of atoms (atomic ontology), the explication of the nature of bonding (based on electrostatic forces rather than electron transfer or sharing), and a better integration of the relationship between bonding and structure. In relation to the literature about scientific modelling, bonding should be taught as an ‘explanation’ of properties of chemicals, rather than a mere ‘description’ of structure. This paper reports an empirical study of a class of Year 10 students’ learning outcomes based on the proposed teaching sequence and emphases. Throughout the learning of the topic ‘chemical bonding’ which spanned two months, three students ranged from the highest to medium achieving students in the class were selected for interviews. Each student was interviewed on four separate occasions in the course of their learning of ‘chemical bonding’. Their understanding of concepts in relation to chemical bonding was probed through their verbal and visual representations. The effectiveness of the teaching sequence was evaluated in the light the alternative conceptions reported in the literature, strategy and suggestions for further improvements were discussed. / published_or_final_version / Education / Master / Master of Education

This study, the effects of computer simulations on the teaching and learning of Atomic Combinations was carried out in the Tshwane North District of Gauteng Province in South Africa. The study employed a non-randomized control-group pre-test and post-test quasi-experimental design involving two grade 11 Physical Science classes; one as an experimental (52) and the other as a control group (53). An Achievement Test consisting of 30 multiple-choice questions and a Structured Questionnaire designed for teacher and learner participants were the principal data collection tools used. The questionnaire was developed to answer research questions two and three that guided this study. The questionnaire tested how much learners and teachers were familiar with the use of computers and if there were any hindrances to computer usage. The achievement test instrument was administered as a pre-test and post-test to answer research question one. The experimental group received computer-assisted teaching and the control group was taught using traditional teaching method (lecture) on the same topics. The intervention took two and a half weeks for each of the schools involved in the study. Analyses of scores of the two groups in post-test were compared using Statistical Package for the Social Sciences (SPSS) independent t-test version 16.0. The results showed that t = 0.467, df = 103, p = 0.048 and the Sig. (2-tailed) value is 0.641. Since sig. (2-tailed) value is greater than 0.05, it can be concluded that there is no statistical significant difference between the experimental group and the control group. / Science and Technology Education / M. Sc. (Mathematics, Science & Technology Education)

This study, the effects of computer simulations on the teaching and learning of Atomic Combinations was carried out in the Tshwane North District of Gauteng Province in South Africa. The study employed a non-randomized control-group pre-test and post-test quasi-experimental design involving two grade 11 Physical Science classes; one as an experimental (52) and the other as a control group (53). An Achievement Test consisting of 30 multiple-choice questions and a Structured Questionnaire designed for teacher and learner participants were the principal data collection tools used. The questionnaire was developed to answer research questions two and three that guided this study. The questionnaire tested how much learners and teachers were familiar with the use of computers and if there were any hindrances to computer usage. The achievement test instrument was administered as a pre-test and post-test to answer research question one. The experimental group received computer-assisted teaching and the control group was taught using traditional teaching method (lecture) on the same topics. The intervention took two and a half weeks for each of the schools involved in the study. Analyses of scores of the two groups in post-test were compared using Statistical Package for the Social Sciences (SPSS) independent t-test version 16.0. The results showed that t = 0.467, df = 103, p = 0.048 and the Sig. (2-tailed) value is 0.641. Since sig. (2-tailed) value is greater than 0.05, it can be concluded that there is no statistical significant difference between the experimental group and the control group. / Science and Technology Education / M. Sc. (Mathematics, Science & Technology Education)

Acompanha: Sequência didática: ligações químicas / O presente trabalho objetivou investigar as concepções alternativas dos alunos de Ensino Médio que usam como referência os livros do Plano Nacional do Livro Didático de Química - PNLD, vigentes no ano de 2016, abordando a temática de ligações químicas, através de uma prática educacional por oficinas e trabalho em equipe. Os resultados desta avaliação orientaram a tabulação dos dados, que foram confrontados com um teste aplicado após o ensino e aprendizagem usando os livros didáticos. A intervenção foi realizada em quatro turmas de Ensino Médio que apresentavam estudantes interseriados e no mesmo nível de conhecimento. Cada turma recebeu um livro vigente do PNLD 2016 durante o bimestre, para estudos sobre as ligações químicas. Verificou-se que os alunos apresentaram confusões entre ligação iônica e covalente, estabilidade das substâncias na formação do octeto, dificuldades na visualização tridimensional das moléculas, observação sobre os eventos do nível observável microscópico e dificuldades na representação das ligações químicas. Concluiu-se também, que os alunos apresentam dificuldades na identificação dos íons formados pelos átomos quando a ligação iônica acontece. Pelos resultados obtidos, percebeu-se que, nos quatro livros do PNLD aplicados no ensino e aprendizagem deste conteúdo químico, os alunos obtiveram resultados significativos de aprendizagem, porém todas as turmas apresentaram concepções alternativas, após os estudos realizados através dos livros. Por fim, com a realização deste trabalho, foi disponibilizada uma sequência didática, apresentando aulas, definindo um procedimento encadeado de passos para tornar mais eficiente o processo de aprendizado dos alunos e pretendendo contribuir com a reflexão e o trabalho dos docentes no Ensino de Química. / The present research aimed to investigate the alternative concepts of High School students who use as reference for his/her studies books of the 2016’s NPDB (National Plan for Chemistry workbooks) approaching the theme of ‘chemical bounding’ through a workshop educational practice and group work. The results of this evaluation guided the tabulation of data, which were faced with a test applied after teaching and learning using textbooks. The intervention was conducted in four high school classes that presented interserial students and the same level of knowledge. Each class received a current book from NPDB 2016 during the Bimaster, for studies on chemical bonds. It was found that the students presented confusion between ionic and covalent bonding, stability of the substances in the formation of the octet, difficulties in the three-dimensional visualization of molecules, observation about the events of the microscopic observable level and difficulties in the representation of the chemical bonds. It was also concluded that students have difficulties identifying the ions formed by the atoms when the ionic connection happens. By the results obtained, it was noted that in the four books of the NPDB applied in the teaching and learning of this chemical content, students obtained significant learning results, but all the classes presented alternate concepts after the studies conducted through the books. Finally, with the realization of this work, a didactic sequence was made available, presenting lessons, defining a procedurechained steps to make the pupils ' learning process more efficient and intend to contribute to the reflection and work of teachers in chemistry teaching.