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1.
Chemical bonding is one of the key and basic concepts in chemistry. The learning of many of the concepts taught in chemistry, in both secondary schools as well as in the colleges, is dependent upon understanding fundamental ideas related to chemical bonding. Nevertheless, the concept is perceived by teachers, as well as by learners, as difficult, with teaching commonly leading to students developing misconceptions. Many of these misconceptions result from over‐simplified models used in text books, by the use of traditional pedagogy that presents a rather limited and sometimes incorrect picture of the issues related to chemical bonding and by assessments of students' achievement that influence the way the topic is taught. In addition, there are discrepancies between scientists regarding key definitions in the topic and the most appropriate models to teach it. In particular, teaching models that are intended to have transitional epistemological value in introducing abstract ideas are often instead understood by students as accounts of ontological reality. In this review paper we provide science educators, curricula developers and pre‐service and in‐service professional development providers an up‐to‐date picture regarding research and developments in teaching about chemical bonding. We review the external and internal variables that might lead to misconceptions and the problematic issue of using limited teaching/learning models. Finally, we review the approaches to teaching the concept that might overcome some of these misconceptions.  相似文献   

2.
The research reported in this study was designed to answer three questions: (a) What misconceptions do eighth grade students have concerning the chemistry concepts from their textbooks. (b) How is reasoning ability related to misconceptions concerning chemistry concepts. (c) How effective are textbooks in teaching an understanding of chemistry concepts? Five chemistry concepts were used in the study: chemical change, dissolution, conservation of atoms, periodicity, and phase change. Problems concerning the five concepts were given to 247 eighth-grade students in order to assess the students' degree of understanding of chemistry concepts and to identify specific misconceptions. Two pencil-and-paper Piaget-type tasks were used to assess intellectual level. A comparison of intellectual level and scores on the chemistry concepts showed moderate correlations. However, the small number of formal operational students in the sample makes these results inconclusive. A study of the level of understanding of the five chemistry concepts and the nature of the misconceptions held by students indicate a general failure of textbooks to teach a reasonable understanding of chemistry concepts.  相似文献   

3.
This paper describes the design and impact of an inquiry-oriented online curriculum that takes advantage of dynamic molecular visualizations to improve students’ understanding of chemical reactions. The visualization-enhanced unit uses research-based guidelines following the knowledge integration framework to help students develop coherent understanding by connecting and refining existing and new ideas. The inquiry unit supports students to develop connections among molecular, observable, and symbolic representations of chemical reactions. Design-based research included a pilot study, a study comparing the visualization-enhanced inquiry unit to typical instruction, and a course-long comparison study featuring a delayed posttest. Students participating in the visualization-enhanced unit outperformed students receiving typical instruction and further consolidated their understanding on the delayed posttest. Students who used the visualization-enhanced unit formed more connections among concepts than students with typical textbook and lecture-based instruction. Item analysis revealed the types of connections students made when studying the curriculum and suggested how these connections enabled students to consolidate their understanding as they continued in the chemistry course. Results demonstrate that visualization-enhanced inquiry designed for knowledge integration can improve connections between observable and atomic-level phenomena and serve students well as they study subsequent topics in chemistry.  相似文献   

4.
This paper describes a case study focusing on the subject matter knowledge, pedagogical content knowledge, and beliefs about science teaching of student teachers in Turkey at the start of their university education. The topic of interest was that of teaching chemical reactions in secondary chemistry education. A written test was developed which used the research literature on potential student misconceptions with regard to different aspects of chemical reactions. Thirty beginning science student teachers were tested, with an additional eight interviews from the student teachers in the same sample. The interviews focused on student teachers’ views about how to best teach chemical reactions in lower secondary chemistry classes. The results revealed deficits in the subject matter knowledge of the student teachers. It also became obvious that the teachers in this sample held very traditional and teacher-centred beliefs when it came to chemistry teaching at the secondary level. Their teaching attitudes were geared mainly towards the acquisition of facts by pupils, and often ignored the development of process-oriented skills. Implications for science teacher education are discussed.  相似文献   

5.
An understanding of the concepts of atom and molecule is fundamental to the learning of chemistry. Any misconceptions and alternative conceptions that students harbor about these concepts will impede further learning. This article identifies misconceptions related to the fundamental characteristics of atoms and molecules which Grade-12 students hold. Data were obtained by administration of semistructured interviews to a stratified, random sample of 30 students of differing abilities and backgrounds in science. Fifty-two misconceptions were observed and are reported. These are grouped into 11 categories. Six relate to the structure, composition, size, shape, weight, bonding, and energy of molecules; five relate to the structure, shape, size, weight, and animistic perceptions of atoms. Some of the misconceptions identified parallel the historical development of scientific concepts.  相似文献   

6.
A test was devised involving familiar chemical examples and administered to samples of Portuguese university chemistry students in order to establish to what extent they recognised and correctly assessed the explanatory content of statements presented in the form of justifications, usually beginning with the word ‘because’. It was found that a high percentage of the students selected as the ‘best explanations’ statements that either involved tautology or simply invoked a rule, principle or general observation. Also, low‐level interpretations and correlations between facts and/or variables (or mathematical concepts) were also frequently taken as valid explanations; more surprising, however, was the finding that a significant proportion of statements involving high level interpretation in terms of fundamental concepts were rated as providing the least intellectual satisfaction.  相似文献   

7.
Modern chemistry concepts have the particulate nature of matter at their core. Chemists explain most phenomena in terms of atomic and molecular models. The lack of understanding of chemistry concepts may be linked to the students' inability to build complete mental models that visualize particulate behavior. With computer animation technology, dynamic and three-dimensional presentations are possible. This study explores the effect of computer animations depicting the particulate nature of matter on college students' mental models of the chemical phenomena. A Particulate Nature of Matter Evaluation Test (PNMET) instrument was used to determine the nature of the students' visualizations and, therefore, their comprehension of the chemical concept studied. Animations were used in two treatment situations: (a) as a supplement in large-group lectures, and (b) as both the lecture supplement and an assigned individual activity in a computer laboratory. These two experimental treatments were compared to a control group. Both treatment groups received significantly higher conceptual understanding scores on the PNMET than did the control group. This increased understanding may be due to the superiority of the formation of more expertlike, dynamic mental models of particle behavior in these chemical processes.  相似文献   

8.
Ensuring that all students, including English language learners (ELLs) who speak English as a second language, succeed in science is more challenging with a shift towards learning through language-intensive science practices suggested by the Next Generation Science Standards (NGSS). Interactive visualization technologies have the potential to support science learning for all students, including ELLs, by providing explicit representations of unobservable scientific systems. However, whether and how such technologies can be beneficial for these underserved students has not been sufficiently investigated. In this study, we examine the short-term and long-term effects of interactive visualizations in improving linguistically diverse eighth-grade students’ understanding of properties of matter and chemical reactions during inquiry instruction. The results show that after interacting with the visualizations, both ELLs and non-ELLs showed significant improvement in their understanding of the target concepts at the molecular level on both the immediate test and the delayed test (3 months after the study). In particular, aligned with the goals of the NGSS, all students, including ELLs, were able to demonstrate their understanding of how energy and matter are involved in chemistry through developing molecular models, critiquing models, and constructing scientific explanations. This study shows the potential benefits of using interactive visualizations during inquiry instruction as a resource to help all students, including ELLs who are traditionally underserved in mainstream classrooms, develop a more coherent understanding of abstract concepts of molecular processes during chemical phenomena.  相似文献   

9.
Illustrative practical work is commonly used in chemistry education to enrich students?? understandings of chemical phenomena. However, it is possible that such practical work may not serve to foster understanding but rather cause further confusion. This paper reports the struggles experienced by a group of senior (Year 12) secondary chemistry students as they sought to understand redox chemical concepts involved in the reactions occurring when steel wool is added to copper sulfate solution. The results showed that the students lacked the skills required to make accurate observations during the practical work. Nor were they able to link the observed phenomena with previously taught redox concepts. The paper also presents possible ways to overcome the difficulties encountered by students as they move between macroscopic and submicroscopic levels of representation of redox reactions.  相似文献   

10.
This study investigated the quality and extent of understanding of certain well-known theoretical concepts which prospective teachers of chemistry in Yemen possess. In addition to the concepts of the conservation of atoms and mass, and the mole, the concepts of atomic mass and balancing chemical equations were chosen for this study. An instrument was built first, then administered to 173 junior and senior prospective chemistry teachers. The results showed that the prospective teachers' understandings of most of the concepts ranged from a partial understanding with specific misconception to no understanding. Only on balancing chemical equations did the prospective teachers show good understanding. The results showed that most prospective teachers depended on mere memorization of the concepts without meaningful understanding. It also found that the prospective teachers' knowledge about the concepts was fragmented and not correlated. The study attributed the prospective teachers' misconceptions to defective instruction. Finally, the study concluded that more effective teaching methods are needed to ensure a sound understanding of these concepts. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 181–197, 1997.  相似文献   

11.
This paper presents findings from a case study into the development of student understanding of a complex and abstract scientific concept: chemical bonding. The case study reveals significant progression in student understanding, but also highlights issues of how such progression should be addressed. Particular emphasis is given to the factors that were associated with ‘blocks’ to appropriate concept development. The learner discussed had her own ‘alternative conceptions’ of ionic charge and electrostatic attraction that, lacking the appropriate background knowledge, she used in order to make sense of chemistry. These alternative ideas blocked the development of an electrostatic framework for bonding to replace the ‘full outer shell heuristic’ used at the General Certificate of Secondary Education (GCSE) level, and had repercussions for the understanding of a range of related concepts. The importance of diagnosing learners’ alternative ideas is thus demonstrated, and some of the problems of carrying out such diagnoses are considered.  相似文献   

12.
A sample of 100 students from junior high school physical science, high school chemistry, and introductory college chemistry were examined for understanding of five chemistry concepts. The concepts addressed were chemical change, dissolution of a solid in water, conservation of atoms, periodicity, and phase change. The amount of experience with the concepts (grade level) and reasoning ability (developmental level) were examined as possible sources of variation in student understanding. Differences in understanding with respect to grade level were found to be significant for the concepts of chemical change, dissolution of a solid, conservation of atoms, and periodicity. However, few of the students in the college chemistry sample exhibited sound understanding of chemical change, periodicity, or phase change. The use of particulate terms (atoms, ions, molecules) increased across the grade levels. Reasoning ability proved to be a significant factor for student understanding of conservation of atoms and periodicity. An examination of the number and types of misconceptions across the grade levels revealed several interesting patterns and suggested sources for the students' alternative conceptions.  相似文献   

13.
Molecular symmetry plays a central role in chemistry education with regard to predicting chemical properties such as bonding and spectroscopic transitions. Better understanding of the symmetry of molecules requires high visual-spatial thinking ability. Conventional teaching methodologies, with limited teaching aides, fall short in providing a detailed understanding of scientific theories and related concepts. Incorrect understanding has been known to perpetrate concepts that are not consistent with the consensus of the research community or alternate conceptions. This work elaborates a methodology designed to discover the alternate conceptions stemming from teaching molecular symmetry in a typical classroom environment and the impact of the virtual laboratory (VL) environment in correcting these misconceptions. Three significant contributions presented in this paper include: (1) the development of a media and information-intense VL experiment platform designed to enhance understanding of symmetry elements and point groups of molecules with diverse structural geometries. (2) the development of an instrument, Molecular symmetry Alternate Conception Test (MACT), designed to capture and estimate the extent of alternate conceptions. (3) the successful identification of typical alternate conceptions amongst students in the context of molecular symmetry. In addition to perceived alternate concepts in symmetry education, the results indicate a significant statistical improvement of 156% in understanding of molecular symmetry concepts (p?<?0.05) after subjecting students to the interactive VL platform. This study also shows identifying bond angles and planarity as concepts crucial for students. It is also implicit that estimations of discrimination skills related to identifying concept-based learning may be relevant for perceiving alternate concepts among learners.  相似文献   

14.
Submicrorepresentations (SMR) could be an important element, not only for explaining the experimental observations to students, but also in the process of evaluating students’ knowledge and identifying their chemical misconceptions. This study investigated the level of students’ understanding of the solution concentration and the process of dissolving ionic and molecular crystals at particulate level, and identifies possible misconceptions about this process. Altogether 408 secondary school students (average age 16.3) participated in the study. The test of chemical knowledge was applied and the analysis of four selected problems related to drawing SMRs in solution chemistry is presented. Selected students were also interviewed in order to gain more detailed data about their way of solving problems comprised in the knowledge test. The average achievement on solution chemistry items was only 43%. It can be concluded from the results that students have different misconceptions about arrangements of solute particles in the solution and presentation of its concentration at particulate level. Students show quite low achievement scores on the problem regarding drawing the SMR of ionic substance aqueous solution (7.6% correct answers) and even lower ones on the problem regarding drawing the SMR of diluted and saturated aqueous solutions of molecular crystal (no completely correct answers). It can be also concluded that many different misconceptions concerning the particulate level of basic solution chemistry concepts can be identified. In the conclusion some implications for teaching to reach a higher level of understanding of solution chemistry are proposed.  相似文献   

15.
The purpose of this research was to investigate students' understanding of electrochemistry following a course of instruction. A list of conceptual and propositional knowledge statements was formulated to identify the knowledge base necessary for students to understand electric circuits and oxidation-reduction equations. The conceptual and propositional knowledge statements provided the framework for the development of a semistructured interview protocol which was administered to 32 students in their final year of high school chemistry. The interview questions about electric circuits revealed that several students in the sample were confused about the nature of electric current both in metallic conductors and in electrolytes. Students studying both physics and chemistry were more confused about current flow in metallic conductors than students who were only studying chemistry. In the section of the interview which focused on oxidation and reduction, many students experienced problems in identifying oxidation-reduction equations. Several misconceptions relating to the inappropriate use of definitions of oxidation and reduction were identified. The data illustrate how students attempted to make sense of the concepts of electrochemistry with the knowledge they had already developed or constructed. The implications of the research are that teachers, curriculum developers, and textbook writers, if they are to minimize potential misconceptions, need to be cognizant of the relationship between physics and chemistry teaching, of the need to test for erroneous preconceptions about current before teaching about electrochemical (galvanic) and electrolytic cells, and of the difficulties experienced by students when using more than one model to explain scientific phenomena.  相似文献   

16.
Cooperative learning is an active learning approach in which students work together in small groups to complete an assigned task. Students commonly find the subject of ‘physical and chemical changes’ difficult and abstract, and thus they generally have many misconceptions about it.

Purpose

This study aimed to investigate the effects of jigsaw cooperative learning activities developed by the researchers on sixth grade students’ understanding of physical and chemical changes.

Sample

Participants in the study were 61 sixth grade students in a public elementary school in Izmir, Turkey.

Design and methods

A pre-test and post-test experimental design with a control group was used, and students were randomly assigned to the experimental and control groups. Instruction of the subject was conducted via jigsaw cooperative learning in the experimental group and via teacher-centered instruction in the control group. During the jigsaw process, experimental group students studied the subjects of changes of state, changes in shape and molecular solubility from physical changes, and acid–base reactions, combustion reactions and changes depending on heating from chemical changes in their jigsaw groups.

Results

The concept test results showed that jigsaw cooperative learning instruction yielded significantly better acquisition of scientific concepts related to physical and chemical changes, compared to traditional learning. Students in the experimental group had a lower proportion of misconceptions than those in the control group, and some misconceptions in the control group were identified for the first time in this study.

Conclusions

Jigsaw cooperative learning is an effective teaching technique for challenging sixth grade students’ misconceptions in the context of physical and chemical changes, and enhancing their motivation, learning achievements, self-confidence and willingness in the science and technology lesson. This technique could be applied to other chemistry subjects and other grade levels.  相似文献   

17.

Many studies have used the potential of computer games to promote students’ attitudes toward learning and increase their learning performance. A few studies have transformed scientific content into computer games or developed games with scientific content. In this paper, we employed students’ common misconceptions of chemistry regarding the properties of liquid to develop a computer game. Daily life situations and everyday phenomena related to the chemical understanding of the properties of liquid were also taken into account. Afterward, we applied a process-oriented, inquiry-based active learning approach to implement the game in a Thai high school chemistry course. We studied the implementation of a game-transformed inquiry-based learning class by comparing it to a conventional inquiry-based learning class. The results of this study include aspects of students’ conceptual understanding of chemistry and their motivation to learn chemistry. We found that students in both the game-transformed inquiry-based learning class and conventional inquiry-based learning class had a significantly increased conceptual understanding of chemistry. There was also a significant difference between the gains of both classes between the pre- and post-conceptual understanding scores. Moreover, the post-conceptual understanding scores of students in the two classes were significantly different. These findings support the notion that students can better comprehend chemistry concepts through a computer game, especially when integrated with the process-oriented, inquiry-based learning approach. The findings of this study also highlight the game-transformed inquiry-based learning approach’s support of students’ motivation to learn chemistry.

  相似文献   

18.
Engineering students in control courses have been observed to lack an understanding of equilibrium and stability, both of which are crucial concepts in this discipline. The introduction of these concepts is generally based on the study of classical examples from Newtonian mechanics supplemented with a control system. Equilibrium and stability are approached in different ways at the various stages of a typical engineering syllabus: at the beginning, they are mostly dealt with a static point of view, for example in mechanics, and are subsequently handled through dynamic analysis in control courses. In general, there is a little clarification of the differences between these concepts or the ways in which they are linked. We believe that this leads to much confusion and incomprehension among engineering students. Several studies have shown that students encounter difficulties when presented with simple familiar or academic static equilibrium cases in mechanics. Our study investigates students’ conceptions and misconceptions about equilibrium and stability through a series of questions about several innovative non-static situations. It reveals that the understanding of these notions is shaken when the systems being studied are placed in inertial or non-inertial moving reference frames. The students in our study were particularly uncertain about the existence of unstable equilibrium positions and had difficulty in differentiating between the two concepts. The results suggest that students use a velocity-based approach to explain such situations. A poor grasp of the above fundamental concepts may result from previous learning experiences. More specifically, certain difficulties seem to be directly linked to a lack of understanding of these concepts, while others are related to misconceptions arising from everyday experiences and the inappropriate use of physical examples in primary school.  相似文献   

19.
Distinctions are drawn between different kinds of learning (such as ‘understanding’, ‘factual knowledge’ and ‘skills’) and between different kinds of learners (such as ‘holist’ versus ‘serialist’ learners, and between ‘visualizers’, ‘verbalizers’ and ‘oers’) so that teaching methods can be matched to them. Learning-centred teaching therefore involves adopting teaching methods, such as ‘student-centred learning’, ‘active learning’, ‘didactive teaching’, ‘problem-based learning’, etc., where they are appropriate, but not where they are inappropriate.  相似文献   

20.
The aim of this paper is to describe a novel modeling and simulation package, connected chemistry, and assess its impact on students' understanding of chemistry. Connected chemistry was implemented inside the NetLogo modeling environment. Its design goal is to present a variety of chemistry concepts from the perspective of emergent phenomena—that is, how macro-level patterns in chemistry result from the interactions of many molecules on a submicro-level. The connected chemistry modeling environment provides students with the opportunity to observe and explore these interactions in a simulated environment that enables them to develop a deeper understanding of chemistry concepts and processes in both the classroom and laboratory. Here, we present the conceptual foundations of instruction using connected chemistry and the results of a small study that explored its potential benefits. A three-part, 90-min interview was administered to six undergraduate science majors regarding the concept of chemical equilibrium. Several commonly reported misconceptions about chemical equilibrium arose during the interview. Prior to their interaction with connected chemistry, students relied on memorized facts to explain chemical equilibrium and rigid procedures to solve chemical equilibrium problems. Using connected chemistry students employed problem-solving techniques characterized by stronger attempts at conceptual understanding and logical reasoning.  相似文献   

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