The impact of polymeric materials on the well-being of citizens of the modern world is enormous. These materials enhance virtually every facet of life--from clothing and personal care items to housing and transportation. Yet despite this, and the fact that most chemists work in a polymer or polymer-related area, polymeric materials have…

Metal oxalate synthesis and pyrolysis provides an opportunity for students to (i) learn stoichiometry, (ii) experience the consequences of proper stoichiometric calculations and experimental techniques, and (iii) be introduced to the relevance of chemistry by highlighting oxalates in context, for example, usages and health effects. At our…

Chemical change is a central theme of Chemistry which has itself been called the central science. This was the title of a popular American text book. I am thus putting forward the idea that chemical change is an idea central to science as a whole, so that it would be one of the ideas children should understand clearly whilst at school. This is…

Learning and presenting chemical concepts at the triple level of chemical concepts provides opportunities for the development of misconceptions. The research aimed to identify potential misconceptions of chemical concepts: the states of matter, a pure substance, a mixture, an element, a compound, a physical change, and a chemical reaction at the…

The main purpose of this study was to investigate the effects of cooperative learning based on conceptual change approach instruction on ninth-grade students' understanding in chemical bonding concepts compared to traditional instruction. Seventy-two ninth-grade students from two intact chemistry classes taught by the same teacher in a public high…

In this paper we present an analysis of chemistry texts (mainly textbooks) published during the first half of the 20th century. We show the evolution of the explanations therein in terms of atoms and of atomic structure, when scientists were interpreting phenomena as evidence of the discontinuous, corpuscular structure of matter. In this process…

The concept of physical and chemical change is far from being the clearest and most self-explanatory concept in the world. If a number of chemists are asked to define physical and chemical change, there may well appear to be a fair degree of uniformity in their answers, until a few examples are suggested. When chemists are asked to place a variety…

This paper discusses seventh-grade students' explanations of dissolution and combustion and also identifies their understanding of the differences between physical and chemical changes. A teaching strategy was initially negotiated within an action research group and this strategy was then employed in teaching seventh-grade students. The teaching…

Focuses on the idea of chemical change and reports data from a study exploring the development of the concept of substance in children aged 11-14. Examines the use of the idea of elements, compounds, and bonding between atoms to explain chemical change and the intersection of these ideas with "basic" particle ideas. (Contains 21 references.)…

Examines how chemistry/science textbooks from different countries and written at different levels of education deal with physical and chemical change. Results indicate that the ideas concerning the teaching and learning of physical and chemical change evident in textbooks are not complete and textbooks seldom justify the content they cover in…

Carries out a naturalistic small-scale study involving a class from a senior high school in Spain over two years. Analyzes students' essays on chemical change using text analysis techniques. Reports the development of four conceptual profiles and the implications of research for the process of teaching the concept of chemical change. (Author/KHR)

The social dimension of chemistry is relevant and present in numerous socio-scientific issues, for example, the use of plastics. These issues can be covered at school by implementing strategies such as role-playing, which allow different perspectives to be understood, thereby helping to promote changes in attitude. This paper presents a…

This qualitative multiple case study explored the conceptual frameworks of two congenitally blind male adolescents on the nature of matter. We examined participants' responses on four tactile investigations focused on concepts and processes associated with matter changes. The matter changes investigated were dissolution, chemical change,…

The colour of the copper layer deposited on a graphite electrode during electrolysis of an aqueous solution of copper(II) sulfate looks whitish-grey when inspected in situ. Taking the electrode out of the solution reveals the familiar orange-red colour of deposited copper. The explanation is found in terms of the almost ideal complementary colours…

We used the Rule Space Model, a cognitive diagnostic model, to measure the learning progression for thermochemistry for senior high school students. We extracted five attributes and proposed their hierarchical relationships to model the construct of thermochemistry at four levels using a hypothesized learning progression. For this study, we…