Teaching the properties of chromium's oxidation states with a case study method

Abstract

The purpose of this study was to investigate how a mixed-method case study affects pre-service science teachers' awareness of hexavalent chromium pollution and content knowledge about the properties of chromium's different oxidation states. The study was conducted in Turkey with 55 sophomores during the fall semester of 2013–2014. The students were taught using a case study about chromium's properties, the qualitative and quantitative analysis methods used with chromium compounds, the effects of chromium compounds on human health, and the chemical techniques that can be used to remove hexavalent chromium from wastewater. Open-ended questions were applied to determine the students' pre- and post-knowledge before and after instruction. An open-ended questionnaire and semi-structured interviews showed that the case study had a positive effect on all participants in terms of increasing their awareness of the hazardous effects of hexavalent chromium. Pair sample and independent samplet-test results revealed that the presenting and the audience groups significantly increased their content knowledge after instruction. On the other hand, while there was no statistically significant difference between the groups on verbal questions, there was a difference between the presenting and the audience groups on calculative questions. This finding shows that the mixed-method case instruction might not have affected all subjects in the same way.

A cross-age study of science student teachers' chemistry attitudes

“…Gardner, 1995;Osborne et al, 2003). This may also indicate that the SSTs perceive the chemists as open-minded people (and/or flexible in their ideas) (Çalık and Coll, 2012;Çalık et al, 2014a, 2014b, 2015. Overall, it can be concluded that a positive female discrimination in National Education and a large number of inquiry-based interventions/curricula (see Çalık and Ayas, 2008;Çalık, 2014) undertaken in the 2000s seem to have accomplished the targeted goals in the case of Turkish context.…”

“…Because the Higher Education Council centrally decides the capacity of each programme (i.e. Ayyıldız and Tarhan, 2012;Hugerat and Kortam, 2014;Özdilek, 2015), context-based approach (Ültay and Çalık, 2012; Ültay et al, 2015), and technology-embedded scientific inquiry (e.g. For this reason, despite the fact that inquiry-based science teaching is theoretically expected, the overcapacity of the teacher education programmes tends to dampen the lecturers' (i.e.…”

“…teacher education programmes), the current capacity of these universities has been increasing year by year and exposing to crowded classes. Ferreira et al, 2013;Çalık et al, 2014a, 2014b, 2015Pietzner, 2014). chemists) use of the chemistry laboratory and inquiry-based methods.…”

A Metodologia De Resolução De Problemas: Uma Experiência Para O Estudo Das Ligações Químicas

“…9,19 Todavia, a maioria dos artigos descreve a utilização do método para o desenvolvimento de habilidades necessárias aos futuros profissionais da Química, 9,[20][21][22] como uso da linguagem, 21 consciência cultural num contexto de globalização econômica, 22 assim como para a aquisição de uma maior consciência ambiental. 19 Em contrapartida, o uso da RP está mais direcionado à aprendizagem de conhecimentos científicos através da resolução de situações-problema. Nessa perspectiva de aprendizagem, um problema é entendido como uma situação que apresenta certo nível de dificuldade e para o qual não se tem de imediato uma solução.…”

“…9,19 Todavia, a maioria dos artigos descreve a utilização do método para o desenvolvimento de habilidades necessárias aos futuros profissionais da Química, 9,20-22 como uso da linguagem, 21 consciência cultural num contexto de globalização econômica, 22 assim como para a aquisição de uma maior consciência ambiental.…”