HIGH SCHOOL STUDENTS’ PROFICIENCY AND CONFIDENCE LEVELS IN DISPLAYING THEIR UNDERSTANDING OF BASIC ELECTROLYSIS CONCEPTS

This study was conducted with 330 Form 4 (grade 10) students (aged 15??C?16?years) who were involved in a course of instruction on electrolysis concepts. The main purposes of this study were (1) to assess high school chemistry students?? understanding of 19 major principles of electrolysis using a recently developed 2-tier multiple-choice diagnostic instrument, the Electrolysis Diagnostic Instrument (EDI), and (2) to assess students?? confidence levels in displaying their knowledge and understanding of these electrolysis concepts. Analysis of students?? responses to the EDI showed that they displayed very limited understanding of the electrolytic processes involving molten compounds and aqueous solutions of compounds, with a mean score of 6.82 (out of a possible maximum of 17). Students were found to possess content knowledge about several electrolysis processes but did not provide suitable explanations for the changes that had occurred, with less than 45?% of students displaying scientifically acceptable understandings about electrolysis. In addition, students displayed limited confidence about making the correct selections for the items; yet, in 16 of the 17 items, the percentage of students who were confident that they had selected the correct answer to an item was higher than the actual percentage of students who correctly answered the corresponding item. The findings suggest several implications for classroom instruction on the electrolysis topic that need to be addressed in order to facilitate better understanding by students of electrolysis concepts.     

Johann Friedrich Wilhelm Adolf von Baeyer

Important discoveries in chemistry most certainly contribute to the industrial and economic developments and indirectly direct the course of history. A majority of Baeyer’s research findings are of this kind. In the pursuit of synthesising a variety of organic compounds for more than half a century, Baeyer became the first chemist who can be considered as classical synthetic organic chemist. He did groundbreaking research in sixteen different areas of organic chemistry, such as dyes, hydroaromatic compounds, polyacetylenes, uric acid and related compounds, natural products. Baeyer’s strain theory is a common textbook topic at the UG level. His work on hydroaromatic compounds strongly supported Kekule’s benzene structure. For this and the work on dyes, he was awarded the 1905 Nobel Prize in Chemistry.     

A Thematic Review of Studies into the Effectiveness of Context-Based Chemistry Curricula

Context-based chemistry education aims at making connections between real life and the scientific content of chemistry courses. The purpose of this study was to evaluate context-based chemistry studies. In looking for the context-based chemistry studies, the authors entered the keywords ??context-based??, ??contextual learning?? and ??chemistry education?? in well-known databases (i.e. Academic Search Complete, Education Research Complete, ERIC, Springer LINK Contemporary). Further, in case the computer search by key words may have missed a rather substantial part of the important literature in the area, the authors also conducted a hand search of the related journals. To present a detailed thematic review of context-based chemistry studies, a matrix was used to summarize the findings by focusing on insights derived from the related studies. The matrix incorporates the following themes: needs, aims, methodologies, general knowledge claims, and implications for teaching and learning, implications for curriculum development and suggestions for future research. The general knowledge claims investigated in this paper were: (a) positive effects of the context-based chemistry studies; (b) caveats, both are examined in terms of students?? attitudes and students?? understanding/cognition. Implications were investigated for practice in context-based chemistry studies, for future research in context-based chemistry studies, and for curriculum developers in context-based chemistry studies. Teachers of context-based courses claimed that the application of the context-based learning approach in chemistry education improved students?? motivation and interest in the subject. This seems to have generated an increase in the number of the students who wish to continue chemistry education at higher levels. However, despite the fact that the majority of the studies have reported advantages of context-based chemistry studies, some of them have also referred to pitfalls, i.e. dominant structure of out-of-school learning, tough nature of some chemistry topics, and teacher anxiety of lower-ability students.     

Fascinating organic molecules from nature

Indigo and Tyrian purple are two dyes which have captured the imagination of the common man as well as the gentry from the very beginning of human civilization. Their story is like a multi-coloured yarn, with strands from chemistry, history, culture and politics. Their popularity is reflected by the fact that their stories are very well documented not only in scientific journals but also in books and even on the celluloid! Recent studies show that indigo may be utilized even as a semi-conducting material.     

The influence of normative beliefs on students’ enrolment choices

Peers, family, mentors and the media may influence students’ attitudes towards chemistry and their intention to enrol in tertiary chemistry courses. In this paper we report on an investigation of the perceptions students hold about their associates’ attitudes towards chemistry and chemists. Data were gathered from interviews with 37 tertiary chemistry students, for whom chemistry had differing roles in their degree. The data suggest that although many of the students’ associates subscribe to stereotypical images of chemistry and chemists, students’ choices of enrolment are predominantly based on their own previous experiences.     

Cognitive restructuring as an early stage in problem solving

This article examines the hypothesis that there are preliminary stages in problem solving which most chemists neglect when trying to teach their students how to solve problems in introductory chemistry courses. It is during these early stages that relevant information is disembedded from the question and the problem is restructured. Unless students can successfully complete these cognitive restructuring stages, they cannot proceed on to the more analytic stages in problem solving that have received more attention from chemists. Preliminary evidence for this hypothesis consists of linear correlations between student ability to handle disembedding and cognitive restructuring tasks in the spatial domain and their ability to solve chemistry problems.     

Jacobus Henricus van’ t Hoff

J H van’ t Hoff is considered as one of the greatest chemists of all time. He started his career as an organic chemist. He solved the vexing problem of optical isomerism by proposing an asymmetric tetrahedral carbon bonded to form different groups. He extended this to include geometric isomerism, and to compounds with heteroatoms in place of asymmetric carbon. Thus he established the ‘chemistry in space’ or stereochemistry. He moved on to work on reaction kinetics, equilibria, thermodynamic properties of dilute solutions and related areas. He laid the foundation for physical chemistry through these discoveries and was awarded the first Nobel Prize in Chemistry in 1901. van’ t Hoff died of tuberculosis at a relatively early age of 59.     

《有机化学》教学规律初探

有机化学的学习要遵循其内在的规律性,而有机化合物的结构、性质及其制备方法是学习的重点.结合生产实践,设计有机化合物的合成工艺路线, 可巩固所学基础理论知识,并通过实验操作以培养学生较强的动手能力和分析问题、解决问题的能力.     

Justus Freiherr von Liebig

Liebig is one of the most honoured and influential scientists of the mid-nineteenth century. Liebig’s major contributions were in the chemistry of fulminates, organic chemistry, agricultural chemistry and physiology. He invented a better technique for C, H and N analysis, which brought about a sort of revolution in the elucidation of molecular structure. His greatness as a teacher is evident from his innovations in teaching methods. He laid the foundation for the modern chemistry curriculum, designed the laboratory layout, and trained a large number of students from all over the world, who became leading, some outstanding, chemists.     

Carbohydrate chemistry from Fischer to now

The story of carbohydrate chemistry from its embryonic stage to the present day high profile research bridging organic chemistry and the life sciences is like a fascinating travelogue through space and time. In this brief article, this intriguing field of natural products chemistry is presented with appropriate illustrations, with the hope that it will kindle further interest in the young readers to whom this is primarily addressed. We begin our journey with Emil Fischer and quickly traverse some areas of classical and modern organic chemistry. In the process we come across some familiar landmarks as well as visit a few exotic places before ending on the borders of biology. Beyond this is a region full of promise inviting further exploration.     

绿色化学在有机化学教学中的渗透

绿色化学是更高层次上的化学,与有机化学有着密不可分的联系。在有机化学教学中可以从不同类型有机反应的原子经济性、不同类有机化合物的性质、有机合成等方面进行绿色化学的渗透。这样既增长学生知识,开拓视野,又增强了学生的环保意识。     

Sir William Henry Perkin: The man and his ‘Mauve’

Today we cannot imagine our lives without a variety of colours. Every colour we see, consume, enjoy, apply and use wherever we need has a dye associated with it. More than 90% of the thousands of dyes used now are synthetic. A little more than 150 years ago a handful of dyes of only natural origin were available. In 1856 the era of synthetic dyes was ushered in by a spirited young chemist, William Henry Perkin, when he was trying to synthesize quinine, but obtained a coloured substance instead. It was a much desired colour and therefore became an instant hit. The following is an account of Perkin’s life as a chemist and an industrialist par excellence.     

National Science Foundation Graduate Teaching Fellows Promote Food Science Education in K-12 Schools in Maine

ABSTRACT: The Univ. of Maine is participating in the National Science Foundation's (NSF) GK-12 Teaching Fellows program. Between 2000 and 2003, 4 food science graduate students demonstrated food- and nutrition-related science lessons, among other innovative activities. This article includes details of an activity on natural dyes to help students understand plant pigments. Assessment of the NSF GK-12 program is ongoing both locally and nationally. NSF's goals are being met, including one of the most important, which is the effect of NSF Fellows as role models on K-12 students.     

有机化学教学中渗透创业教育探析

有机化学作为高校的基础学科,在给学生传授有机化学的专业基础知识的同时．应注重激发学生创业意识,提高学生就业能力,转变教育教学理念,促进有机化学课程改革。要运用启发引导教育法,培养学生创新创业意识;运用探索试验教育法,优化学生创新创业思路;运用类比创新教育法,提高学生创新创业能力;运用借鉴移植教育法,搭建学生创新创业平台,通过多种方式鼓励学生转变就业观念,将创业作为未来职业的一种选择。     

Students’ Conceptions About ‘Radiation’: Results from an Explorative Interview Study of 9th Grade Students

One basis of good teaching is to know about your students?? preconceptions. Studies about typical ideas that students bring to the science classroom have been and continue to be a major field in science education research. This study aims to explore associations and ideas that students have regarding ??radiation??, a term widely used in various fields and necessary to understand fundamental ideas in science. In an explorative study, the perceptions of 50 high school students were examined using semi-structured interviews. The students were 14?C16?years old and were chosen from 7 different high schools in an urban area in Austria. Following an interview guideline, students were asked about their general associations with the term ??radiation?? as well as about their general understanding of different types of radiation. A qualitative analysis of these interviews following the method of Flick (2009) revealed that the students?? associations were, to a great extent, very different from the scientific use of the term. Several conceptions that could inhibit students?? learning processes could be identified. Consequences for the teaching of the topic ??radiation?? in science lessons, which are based on these preconceptions, are presented in the conclusion.     

Chemistry for whom? Gender awareness in teaching and learning chemistry

Marie Ståhl and Anita Hussénius have defined what discourses dominate national tests in chemistry for Grade 9 in Sweden by using feminist, critical didactic perspectives. This response seeks to expand the results in Ståhl and Hussénius’s article Chemistry inside an epistemological community box!—Discursive exclusions and inclusions in the Swedish national tests in chemistry, by using different facets of gender awareness. The first facet—Gender awareness in relations to the test designers’ own conceptions—highlighted how the gender order where women are subordinated men becomes visible in the national tests as a consequence of the test designers internalized conceptions. The second facet—Gender awareness in relation to chemistry—discussed the hierarchy between discourses within chemistry. The third facet—Gender awareness in relation to students—problematized chemistry in relation to the students’ identity formation. In summary, I suggest that the different discourses can open up new ways to interpret chemistry and perhaps dismantle the hegemonic chemistry discourse.     

Comparison of learning in two context-based university chemistry classes

ABSTRACT

Context-based learning (CBL) is advocated as beneficial to learners, but more needs to be understood about how different contexts used in courses influence student outcomes. Gilbert defined several models of context that appear to be used in chemistry. In one model that achieves many criteria of student meaning-making, the context is provided by ‘personal mental activity’, meaning that students engage in a role to solve a problem. The model’s predicted outcomes are that students develop and use the specialised language of chemistry, translate what they learn in the immediate context to other contexts, and empathise with the community of practice that is created. The first two of these outcomes were investigated in two large-enrolment university chemistry courses, both organised as this CBL model, in which students were introduced to kinetic molecular theory (KMT). Sample 1 students (N₁?=?105) learned KMT through whole-class kinaesthetic activity as a human model of a gas while focusing on a problem identifying substances in balloons filled with different gases. Sample 2 students (N₂?=?110) manipulated molecular dynamics simulations while focusing on the problem of reducing atmospheric CO₂. Exam answers and pre-/post-test responses, involving a new KMT context, were analysed. Students in Sample 1 demonstrated a stronger understanding of particle trajectories, while Sample 2 students developed more sophisticated mechanistic reasoning and greater fluidity of translation between contexts through increased use of chemists’ specialised language. The relationships of these outcomes to the contexts were examined in consideration of the different curriculum emphases inherent in the contexts.     

Positions Toward Science Studies in Medicine Among University Graduates of Medicine and the Teenaged Participants of the ��Medical Systems�� Study Program

The ??Medical Systems?? program was designed to introduce high school students to the world of advanced medicine. Its premise was to use an applied scientific discipline like medicine to encourage high-school students?? interest in basic science. This study compares the teen-aged graduates of ??Medical Systems?? with fourth and fifth-year medical students. It aims to identify the attitudes of these two groups towards medical science and basic sciences in medicine. The population included 94 graduates of ??Medical Systems?? from schools throughout Israel, who had also completed an advanced-level course in a basic science (biology, chemistry or physics), and 96 medical students from different Israeli universities. The students?? attitudes were measured using West et al.??s questionnaire (Med Educ 16(4):188?C191, 1982), which assesses both the attitude of the participants towards basic science knowledge, and their attitude towards their learning experience in medical school. Nine participants from each group were also interviewed using a semi-structured interview protocol. The results showed essential differences in the attitudes of the two groups. The high school students consider scientific knowledge far more essential for a physician than do the medical students, who also showed a far lower estimation of the effectiveness of their science studies.     

Making a Theist out of Darwin: Asa Gray’s Post-Darwinian Natural Theology

In March of 1860 the eminent Harvard Botanist and orthodox Christian Asa Gray began promoting the Origin of Species in hopes of securing a fair examination of Darwin??s evolutionary theory among theistic naturalists. To this end, Gray sought to demonstrate that Darwin had not written atheistically and that his theory of evolution by natural selection had not presented any new scientific or theological difficulties for traditional Christian belief. From his personal correspondence with the author of the Origin, Gray well knew that Darwin did not affirm God??s ??particular?? design of nature but conceded to the possibility that evolution proceeded according to ??designed laws.?? From this concession, Gray attempted to develop a post-Darwinian natural theology which encouraged theistic naturalists to view God??s design of nature through the evolutionary process in a manner similar to the way in which they viewed God??s Providential interaction with human history. Indeed, securing a fair reading of the Origin was not Gray??s sole aim as a promoter of Darwinian ideas. In Darwin??s theory of natural selection, Gray believed he had discovered the means by which a more robust natural theological conception of the living and evolving natural world could be developed. In this paper I outline Gray??s efforts to produce and popularize a theistic interpretation of Darwinian theory in order to correct various misconceptions concerning Gray??s natural theological views and their role in the Darwinian Revolution.     

Development and Assessment of A Diagnostic Tool to Identify Organic Chemistry Students’ Alternative Conceptions Related to Acid Strength

The central goal of this study was to create a new diagnostic tool to identify organic chemistry students’ alternative conceptions related to acid strength. Twenty years of research on secondary and college students’ conceptions about acids and bases has shown that these important concepts are difficult for students to apply to qualitative problem solving. Yet, few published studies document how students’ prior knowledge of acids influences their understanding of acid strength in organic chemistry contexts. We developed a nine-item multiple-tier, multiple-choice concept inventory to identify alternative conceptions that organic chemistry students hold about acid strength, to determine the prevalence of these conceptions, and to determine how strongly these conceptions bias student reasoning. We identified two significant alternative conceptions that organic chemistry students hold about acid strength. Students who answered items incorrectly were more confident about their answers than peers who answered items correctly, suggesting that after one semester of organic chemistry, students do not know what they do not know. Implications for the teaching of acid strength are discussed.