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Learners who pass the South African National Senior Certificate (NSC) physical sciences examination generally show a weak conceptual understanding of chemistry at university. This inconsistency was investigated by examining strategies used in the teaching of chemical equilibrium in schools. A combination of on-site observations, journaling and teacher interviews was used in a survey of 4 teachers in 3 well-resourced schools whose learners regularly achieve good results in the subject. In this article we argue that, whereas the study reported on here revealed a high degree of consistency in basic concept teaching approaches calculated to help learners pass the NSC examination, focus on the examination comes at the expense of in-depth exploration of concepts. We found that Grade 12 chemistry teachers value learners' success in the NSC examination more than their understanding of concepts and ability to use those concepts beyond the examination. Reasons for, as well as consequences of this strategic choice were identified and are discussed.

The aim of this research is to take a fresh look at the physical science concepts that Year 3 students struggle with. In this work, the responses of over 8,000 middle-primary-aged students to a range of physics, space science and chemistry questions were evaluated. The questions covered a number of topics ranging from selecting and using simple measurement tools to changes of state. From the student responses, we were able to address the following questions: 'Which physical science concepts did the students find difficult?' and 'Are the identified concepts the same concepts that students struggled with in the past or have new difficulties emerged?'. From the responses, it was determined that difficult concepts for Year 3 included: bigger objects don't always weigh more than smaller objects; gases have mass and volume; and day and night is caused by the Earth spinning on its axis. We summarise these findings along with recommendations for the Year 3 classroom.

We experience (perceive, act upon and react to, and conceptualize) dynamical processes in nature as agentive. Expressed differently, we experience events as resulting from activities and interactions of "Forces of Nature" (such as wind, light, heat, fluids, electricity, substances, and motion) that are conceived of as powerful agents acting and interacting in physical environments. An example would be sunlight creating heat in the Earth's surface layers, and this heat using the atmosphere as a heat engine whose output are the winds on our planet. In the physics of dynamical systems, these forces are characterized in terms of intensive and extensive quantities (i.e., electric potential and electric charge in the case of electricity). The aspect of power is formalized with the help of a generalized energy principle and the rules relating power/energy to intensive and extensive physical quantities. Concrete processes depend upon properties of physical materials (in and through which forces are active) such as (thermal, electrical, etc.) capacity or conductivity. In this paper, we demonstrate how we can create "Embodied Simulations" and "Forces-of-Nature Theater" performances, where children act as forces such as water, heat, electricity, and motion. The embodied logic of the physical play teaches children about the logic of our explanations of physical processes.

This study explored the perceptions of teachers and learners regarding the use of Process Oriented Guided Learning Inquiry Learning (POGIL) to teach stoichiometry. A qualitative case study was carried out at two conveniently and purposively sampled township schools in Pretoria, South Africa. For this purpose, two Grade 11 physical sciences classes were identified where 48 learners and their respective teachers, who had previously been trained to teach using POGIL, gave consent to participate in the study. Data were collected using lesson observations, focus group interviews for learners and interviews for teachers. All data were transcribed and analysed with the aid of ATLAS.ti software for qualitative data analysis. The findings from the observations indicate that the learners were excited, motivated, and actively engaged in their work. They assisted one another by attempting to answer questions supported with justification. The findings from the focus group interviews indicate that the learners were excited to learn using POGIL and wished to use the method in other subjects, including mathematics. The learners had noticed improvements in their grades and understanding of abstract topics. The findings from the teacher interviews indicated that they appreciated POGIL because they found it useful in reducing misconceptions, increasing learner participation, increasing understanding and achievement, and that their learners were more engaged. The results indicate that POGIL increased learners' interest, participation and active learning, while seemingly also improving the learners' understanding of and achievement in abstract topics like stoichiometry. POGIL may be useful in increasing active learning and participation of learners which may lead to increased understanding and achievement.

Wildland fires have become a regular aspect of life for people living in the western United States. Wildfire smoke is now impacting air quality across the United States. Unprecedented wildfires have swept through Australia, Russia, and Portugal in the last few years. Like other natural disasters, wildland fires can have a devastating impact on communities that are directly in their paths. However, they also cast a much bigger footprint due to the smoke they release on a global scale. These smoke events can lead to health warnings, noticeable irritation to the lungs, and cancelled outdoor events. They have quickly become part of the life experience of many students around the world. Their connections to global climate change and environmental policy, juxtaposition as positive forces in ecosystem succession, and relationship to a wide variety of both simple and complex natural phenomena leave science teachers with an opportunity to frame myriad lessons within the context of wildfire. This article presents a series of such lessons, adaptable to various levels of physical or integrated science. This series of lessons was taught in 9th- and 10th-grade physical science classes with students who are regularly affected by intense wildfire smoke. The learning sequence would also be appropriate for general chemistry and physics courses and can be easily adapted to meet the academic level of the students. The lessons were adapted for online instruction in response to the COVID-19 pandemic.

Despite advances in software development, symmetry-related topics are among the most important yet confusing concepts in crystallography training for chemistry students who routinely use small-molecule crystallography in their scientific study. The case-based learning approach is very effective in stimulating students' interests in self-exploring the course material and critically processing information to arrive at the most reasonable result. Learning modules such as applying concepts of the 17 two-dimensional space groups in Escher drawings and critically judging crystallography misconceptions can engage chemistry students and invoke their confidence in handling the crystal structures encountered in their research.

Potassium tris(oxalato)ferrate(III) trihydrate is a commonly prepared coordination compound in general or upper-level chemistry laboratories and can be recycled to grow large single crystals that instructors may display when introducing the experiment to classes. Showing the crystal's shape can also be used to briefly introduce students to X-ray crystallography, symmetry, and unit cell dimensions.

In the United States, research on beginning science teachers provides little guidance regarding empirical minimum levels of discipline-specific science coursework for sufficient subject matter knowledge to teach science. Accordingly, in this study we analyzed secondary physical science teachers' science coursework for subject matter knowledge (SMK) and resulting misconceptions of chemistry and physics concepts. Findings were compared with state-level science teacher certification policies. Participants had either: (a) completed a master's level teacher preparation program with an undergraduate degree in science, (b) completed an undergraduate teacher preparation program with a minor degree or more in science, or (c) were undergraduate students enrolled in science courses required for chemistry and physics teacher certification. We analyzed participants' transcripts for discipline-specific science coursework credit hours and GPAs and identified possible predictors of SMK predictors of the likelihood of passing chemistry and physics misconceptions tests. We categorized teachers' level of SMK and used multiple variable and logistic regressions (n = 212 participants; n = 109 chemistry and n = 103 physics). To identify teacher candidates' possible misconceptions, we analyzed chemistry (n = 97) and physics (n = 91) participants' item responses with the corresponding science credit hours and GPAs. With increasing numbers of credit hours teachers held fewer misconceptions. However, even with medium to high SMK levels, teachers still held misconceptions about chemical bonding, electromagnetism, and Newton's laws until they reached critical credit hour and GPA thresholds. Lastly, we provide recommendations for physical science teachers' programs of study and state-level teaching certification policies, using empirical minimum quantity and quality of chemistry, physics, and mathematics coursework.

Powder diffraction is one of the most widely used analytical techniques for characterizing solid state materials. It can be used for phase or polymorph identification, quantitative analysis, cell parameter determination, or even full crystal structure analysis using the powerful Rietveld refinement method. As with much of modern crystallography, the software used for Rietveld refinement is frequently treated as a "black box" that produces often poorly understood outputs. This paper shows how it is possible for students to perform a full Rietveld refinement against experimental powder diffraction data from scratch using a simple spreadsheet like Excel. It starts by reviewing the basic ideas of least-squares fitting a straight line, develops these into fitting simple functions to peaks in simulated experimental data, and then combines these ideas with crystallographic equations to enable Rietveld refinement of the structure of an inorganic material (rutile, TiO2). At each stage, students can self-learn different fundamental aspects and pitfalls of data analysis that are widely reapplicable. The ideas can be taught as an online learning exercise or could be incorporated in a laboratory class where students collect and analyze their own experimental data.

The study investigated the effect of problem-based learning (PBL) on students' achievement in chemistry. Learners' low achievement in Science in South Africa has been a concern to government, stakeholders, school principals and parents over the years as a result of poor teaching techniques, students' attitudes, lack of teaching and learning materials, teachers' pedagogical skills, etc. Several studies, for instance the Monitoring Learner Achievement (MLA) project conducted by UNESCO and UNICEF have shown no improvement in the performance of South African students in Mathematics and Science. Quasi-experimental design was employed for the study. 101 equivalent students were selected for the study using pre-test. The control group was taught with the traditional lecture method whiles the experimental group received instruction with PBL. Independent t-test was used for the analysis. Results showed that there was significant difference (p < 0.05) in chemistry achievement of students between control and the experimental group while there was no significant differences in the before the study. The results show that PBL is an effective way for to teach chemistry so as to improve students' critical thinking and problem solving skills.

This communication describes the actions undertaken to translate the chemical crystallography course at the University of Novi Sad, Serbia, from face-to-face to online instruction, as well as the emerging challenges encountered during this unprecedented time. As part of the global efforts to respond to the recent disruptions to teaching, our purpose in this paper was to provide insights about useful methods that can be used in chemical crystallography courses to alleviate the concerns resulting from this shift in modality and to point out to some aspects of teaching that did not work as expected, despite the optimum efforts.

This mixed method study investigated changes in 3rd year Bachelor of Education students' attitudes towards chemistry after learning interventions with virtual chemistry simulations. After participant students identified certain concepts from their 3rd year chemistry module as being abstract and not easily comprehensible, these concepts were facilitated during a 5 week learning intervention using PhET simulations as an alternative to traditional laboratory experimentation. In the first quantitative phase of the study, a 30-item pre-attitude test was administered to assess students' attitudes towards chemistry, followed by PhET chemistry simulation learning interventions. Thereafter, students wrote a post-attitude test. Findings of this phase revealed a significantly higher mean post-attitude test score, with students showing a positive attitude towards chemistry learning, post-intervention. The quantitative phase was followed by a qualitative phase which examined students' experiences on the use of simulations through semi-structured interviews. Findings from the qualitative phase revealed that students experienced autonomy and enjoyment during engagement with the simulations. They also perceived that their experiences in the virtually simulated environment improved their visualisation of chemistry concepts, thereby improving conceptual understanding. However, the students acknowledged that simulations cannot replicate the realism and authenticity associated with practical work in an actual laboratory. The implications of these findings are that virtual simulations provide a complementary learning tool capable of improving students' attitudes towards chemistry, and perceived by students to support their visualisation of abstract chemistry concepts. The findings of this study are particularly significant for chemistry learning at schools and universities in economically challenged countries such as South Africa where there is a shortage of well-equipped laboratories.

In French nursery schools ("l'école maternelle française"), primary school teachers take charge of the content organised into teaching areas of activities. The prescribed teaching activity "Discovering the world of life sciences, objects and material" refers to biology, physical sciences, chemistry and technology. The children's learning path concerning these worlds represents the early stages of the curriculum. Many research studied these children's learning (e.g. Bisault, 2005; Fleer, 1996; Ravanis & al., 2013). This paper focuses on teachers and aims at describing and analysing the implementation of the practices of this early childhood education. In a curriculum perspective (Dillon, 2009; Martinand, 2003; Ross, 2000), an inquiry about the practices reported both in teachers' logs and questionnaires, reveals the contents, activities and issues associated with these educational experiences. The results show biology is privileged and preferred to technology by the teachers. The research indicates an interrelated scientific and technological curriculum and a science and technology mostly found, in what I called, "compositional schemes". The discovery of this world, through these compositional schemes, takes various positions according to the priorities assigned by the teachers. The research at last allows me to discuss the professional training of preschool teachers in order to improve the teaching practices in science and technology.

This laboratory experiment demonstrates the important utility of transition-metal complexes as catalysts in the addition reaction of carbon tetrabromide (CBr ) to select alkenes. This application offers students the opportunity to understand why transition-metal complexes are worth synthesizing. The experiment builds on fundamental theories presented during first-year general chemistry courses and integrates concepts taught in organic chemistry, inorganic chemistry, organometallics, and instrumental analysis. It incorporates some advanced laboratory practices for students to assimilate with, such as literature searches and interpretation; organometallic compound analysis; catalysis experiment design; reaction mechanisms; NMR spectroscopy with comprehensive spectra interpretation; and X-ray crystallography.

Mechanistic reasoning, or reasoning systematically through underlying factors and relationships that give rise to phenomena, is a powerful thinking strategy that allows one to explain and make predictions about phenomena. This article synthesizes and builds on existing frameworks to identify essential characteristics of students' mechanistic reasoning across scientific content areas. We argue that these characteristics can be represented as "epistemic heuristics," or ideas about how to direct one's intellectual work, that implicitly guide mechanistic reasoning. We use this framework to characterize middle school students' written explanatory accounts of two phenomena in different science content areas using these heuristics. We demonstrate evidence of heuristics in students' accounts and show that the use of the heuristics was related to but distinct from science content knowledge. We describe how the heuristics allowed us to characterize and compare the mechanistic sophistication of account construction across science content areas. This framework captures elements of a crosscutting practical epistemology that may support students in directing the construction of mechanistic accounts across content areas over time, and it allows us to characterize that progress.

Technological innovation in science provides complementary tools for exploring new teaching strategies within a pedagogical framework that promotes interaction between the teacher and the learner. This work is based on the implementation of a computer application modeling crystallographic material structures, in order to identify and study the different crystalline structures and their characteristics, based on the techniques of three-dimensional modeling covering the OpenGL library and the Euler rotation matrices, and developed by the C # programming language. The analysis and design of this study ranging from the study of the existing, the identification of the problematic, modeling and development, and finally the validation tests. Our research is aimed at second-year chemistry students at Ben M'sik Faculty of Science, Hassan II University of Casablanca, Morocco. We wish to conduct a comparative study between classical methods and after numerical simulation, in order to identify didactic factors influencing the cognitive engagement of learners. The results were good, 89.20% of students in the first group who worked on manipulations using the simulation application scored above 15/20, and 90.22% scored above 15.20./20 for the second group after completion of the manipulations according to the two modalities (traditional and computer). Teachers mentioned that the results have been favorable and support the recommended educational objectives for effective integration of this computer system, which seems to be effective for students who have tried to interact with the practical work to understand the phenomenon of crystallography by a virtual simulation on computer.

Stoichiometry, which deals with the quantitative aspects of Chemistry, is a topic students find challenging and which teachers struggle to teach. South African students' performance in stoichiometry in the final matriculation examinations has led to calls for the topic to be taught better and highlighted the need for teacher professional development. This served as the rationale for this study to design an instrument to measure the quality of experienced Physical Science teachers' topic-specific pedagogical content knowledge (TSPCK) using a mixed-methods approach. Responses by five teachers to open questions on each of five components of TSPCK were used to generate scenario-based items for the instrument. The validity of the instrument was determined through Rasch analysis of responses of a sample of 31 teachers. Both the validity and reliability of the instrument to measure the quality of TSPCK in stoichiometry were found to be acceptable based on the fit statistics and reliability measures generated from the Rasch analysis.

This case study analyzes five science courses of a United States virtual charter school. Online quizzes and exams are provided by the corporate partner, while local teachers have selected report topics, virtual labs and at-home labs for students to complete. These assessments were coded for their correlation to the cognitive levels of the revised Bloom's taxonomy and the US NSES (National Science Education Standards). The remembering level was associated with the largest number of quiz and exam questions. However, analysis and application were also frequently assessed. Most of the standards were assessed at some point. The teacher selected projects address science inquiry standards but not additional content standards. The projects often required higher levels of thinking. Recommendations for teachers in virtual K-12 (kindergarten through 12th grade) schools are made to select additional content that focuses on key concepts and include more application, analysis, evaluation and creation. (Contains 7 tables.)

I report on an analysis of the alignment between the South African Grade 12 Physical Sciences core curriculum content and the exemplar papers of 2008, and the final examination papers of 2008 and 2009. A two-dimensional table was used for both the curriculum and the examination in order to calculate the Porter alignment index, which indicates the degree of match between the two. Alignment indices of 0.8 and 0.6 for Physics and Chemistry, respectively, were computed and remained constant for Physics, but fluctuated initially for Chemistry before levelling off. Using the revised Bloom's taxonomy, discrepancies were found in terms of cognitive levels as well as content areas in both Physics and Chemistry. The cognitive level Remember is under-represented in the Chemistry and Physics examinations, whereas the cognitive levels Understand and Apply were over-represented in Chemistry. It is argued that the shift to higher cognitive levels is in line with the reported increase in cognitive complexity of the Physical Sciences curriculum. The significance of the study for Physical Science teachers is highlighted, and the potential for further research is also indicated.

This paper describes the results of a comparative study into the approaches used by science undergraduates when solving open-ended problems. This study adopted a pseudo-grounded theory framework to analyse six case studies, one from each of the science disciplines studied. The study involved 70 participants from 5 institutions solving open-ended problems using a think-aloud protocol. Analysis of the data identified a number of different approaches used by each subject group. Participants in psychology, pharmacy and sports rehabilitation used a greater number of novice-like approaches than participants in chemistry, physics and interdisciplinary science. The approaches used by physical science participants were very similar whereas those from pharmacy, sports rehabilitation and psychology were more varied and relied on students' ability to relate to a familiar context. Evaluation of the relative quality of solutions showed variation with discipline.

Previous research on students' difficulties in learning chemical equilibrium has shown that students hold misconceptions about this topic, and this often results in unintended learning. However, recent developments in human learning from the behavioural sciences perspective indicate that students' difficulties in learning are much more than misconceptions. The purpose of the study was to identify the knowledge and skills that students lack in successfully solving chemical equilibrium problems involving calculation of the equilibrium constant, K[subscript c]. Participants of this study included three students from a high-achieving school and four students from a low-achieving school in the Bohlabela district of Mpumalanga province of South Africa. Data sources included transcripts of students' think-aloud protocols, video recordings of students' problem-solving performance and students' written answers. Results showed that students at the low-achieving school applied personal algorithms exclusively at a superficial level in all phases of the problem-solving process, and committed many errors. Their main difficulty was a lack of conceptual awareness of how a chemical reaction progresses to equilibrium. On the other hand students at the high-achieving school demonstrated conceptual understanding in solving problems in familiar contexts, but lacked the skills for dealing with problems in an unfamiliar context; few errors were observed in their solutions. The results suggest that contextual knowledge is of a higher-order type, and is likely to emerge after students have acquired considerable skills in self-regulation. The implications of the results for teaching of chemical equilibrium are discussed.

The Science Belief Test is an online instrument comprised of 47 statements that require true or false responses and request written explanations to accompany these responses. It targets topics in chemistry, physics, biology, earth science, and astronomy and was initially designed to assess preservice elementary teachers' beliefs about general science content. A set of responses for six of the physical science items targeting force/gravity and physical/chemical change was selected for analysis from 305 respondents. Written explanations were coded into three general categories: (1) correct explanation, (2) incorrect explanation, (3) guess or uninterpretable. The correct response rates for the explanations were compared to the correct response rates that were based on the accompanying true or false answers. The explanations were further analyzed and coded into specific categories that included alternative and naive conceptions. Correct response rates, when analyzed from the true/false or written explanations, were low (less than 60%) for five of the six items. Naive beliefs and/or misconceptions were prevalent for each of these five items, and understanding that students may hold these beliefs prior to instruction may provide teachers with useful information for the purpose of improving instruction. (Contains 2 tables.)

Teachers contribute enormously to a positive social climate in science classes, particularly through their communication with students. In the study described in this article, a questionnaire [The Teacher Communication Behaviour Questionnaire (TCBQ)] developed by She and Fisher (2000) was used. TCBQ can be used to assess students' perceptions of science teachers' interpersonal communication behaviours in their classroom learning environments. TCBQ has five scales: Challenging, Encouragement and Praise, Non-Verbal Support, Understanding and Friendly, and Controlling. The TCBQ was used with a large sample of university students in Turkey. Girl students perceived more of these communication behaviours in their teachers than did the boy students. There were statistically significant differences (p less than 0.0001) on four of the five scales of the TCBQ between teachers' gender. Statistically significant differences were not found among different grade classes. Teachers in biological and chemistry science classrooms exhibited more favourable behaviour toward their students than did those in physical science classrooms. (Contains 4 tables.)

In many countries there remain substantial sex differences in enrolments in elective science courses, despite concerted efforts in recent years to alleviate them. This paper explores the reasons for these differences by comparing models of male and female enrolment intentions in elective courses in biology, chemistry and physics. The models are based on responses from approximately 450 students from 5 Australian high schools. First, a theoretical model, the Science Enrolment Model, was derived from Eccles and colleagues' General Model of Academic Choice. Students' responses were then used to develop empirical models of enrolment intentions in the three elective courses. Analyses for the models were conducted using the LISREL "mean structures" extension. Sex differences in the dependent variables in the models were then attributed to the relevant sets of independent variables. Substantial sex differences were identified in measures of perceived career value, interest and performance expectations in all three models which explained between 70% and 82% of the sex differences in enrolment intentions. (Contains 1 table and 5 figures.)

This article describes the implementation and application of a metal deposition and surface diffusion Monte Carlo simulation in a physical chemistry lab course. Here the self-diffusion of Ag atoms on a Ag(111) surface is modeled and compared to published experimental results. Both the thin-film homoepitaxial growth during adatom deposition onto a single-crystal surface and the agglomeration of grown nanostructures due to Ostwald ripening during a heating experiment are simulated. In addition, a Monte Carlo classroom experiment is presented that simulates the random walk of a single Ag atom on the Ag(111) plane. These two Monte Carlo simulations allow for the teaching of random walk, surface diffusion, island formation, and agglomeration. The universal Arrhenius law is evaluated for thermally activated processes.

Recent science reform documents have called for incorporating authentic scientific discourse into science classes as engaging in discourse has shown to result in numerous benefits. Whether these benefits are observed in students depends upon the quality of the discourse in which they engage. However, characterizing the quality of student-student discourse can be an ambiguous task. In this work, we introduce decentering as one feature of effective student-student interactions that can be used to evaluate the quality of discourse. Decentering refers to the process of differentiating between one's own perspective and another's. Arguments from two process-oriented guided inquiry learning physical chemistry classes are presented to illustrate this concept. Decentering manifests itself in these arguments through careful consideration of alternative arguments. Practitioners and researchers can use the results of this study to facilitate and analyze student-student discourse.

The concept of wave-particle duality in quantum theory is difficult to grasp because it attributes particle-like properties to classical waves and wave-like properties to classical particles. There seems to be an inconsistency involved with the notion that particle-like or wave-like attributes depend on how you look at an entity. The concept comes into more clear focus with the precise language of mathematics and with an experiment or demonstration of quantum interference that involves the scattering of photons by a single slit. After describing a photon as a quon, a quantum-sized entity, a precise description of the interference of quantum probability amplitudes allows determination of the photon wavelength by classical measurements of laboratory observations.

This study examines Saudi Arabian middle school science textbooks' coverage of the essential features of scientific inquiry. All activities in the middle school science textbooks and workbooks were analyzed by using the scientific inquiry "essential features" rubric. The results indicated that the essential features are included in about 59% of the analyzed science activities. However, feature 2, "making learner give priority to evidence in responding to questions" and feature 3, "allowing learner to formulate explanations from evidence" appeared more frequently than the other three features (feature 1: engaging learner in scientifically oriented questions, feature 4: helping learner connect explanations to scientific knowledge, and feature 5: helping learner communicate and justify explanations to others), whether in the activities as a whole, or in the activities included in each of the four science domains (physical science, Earth science, life science and chemistry). These features are represented in almost all activities. This means that almost all activities in the middle school science textbooks and the workbooks include features 2 and 3. Meanwhile, the mean level of inclusion of the five essential features of scientific inquiry found in the middle school science textbooks and workbooks as a whole is 2.55. However, results found for features 1, 4, 5 and for in-level inclusion of the inquiry features in each of the science domains indicate that the inclusion of the essential inquiry features is teacher-centred. As a result, neither science textbooks nor workbooks provide students with the opportunity or encouragement to develop their inquiry skills. Consequently, the results suggest important directions for educational administrators and policy-makers in the preparation and use of science educational content.