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Reported herein are thermochemical studies of hydrogen atom transfer (HAT) reactions involving transition metal H-atom donors M(II)LH and oxyl radicals. [Fe(II)(H(2)bip)(3)](2+), [Fe(II)(H(2)bim)(3)](2+), [Co(II)(H(2)bim)(3)](2+), and Ru(II)(acac)(2)(py-imH) [H(2)bip = 2,2'-bi-1,4,5,6-tetrahydropyrimidine, H(2)bim = 2,2'-bi-imidazoline, acac = 2,4-pentandionato, py-imH = 2-(2'-pyridyl)imidazole)] each react with TEMPO (2,2,6,6-tetramethyl-1-piperidinoxyl) or (t)Bu(3)PhO(*) (2,4,6-tri-tert-butylphenoxyl) to give the deprotonated, oxidized metal complex M(III)L and TEMPOH or (t)Bu(3)PhOH. Solution equilibrium measurements for the reaction of [Co(II)(H(2)bim)(3)](2+) with TEMPO show a large, negative ground-state entropy for hydrogen atom transfer, -41 +/- 2 cal mol(-1) K(-1). This is even more negative than the DeltaS(o)(HAT) = -30 +/- 2 cal mol(-1) K(-1) for the two iron complexes and the DeltaS(o)(HAT) for Ru(II)(acac)(2)(py-imH) + TEMPO, 4.9 +/- 1.1 cal mol(-1) K(-1), as reported earlier. Calorimetric measurements quantitatively confirm the enthalpy of reaction for [Fe(II)(H(2)bip)(3)](2+) + TEMPO, thus also confirming DeltaS(o)(HAT). Calorimetry on TEMPOH + (t)Bu(3)PhO(*) gives DeltaH(o)(HAT) = -11.2 +/- 0.5 kcal mol(-1) which matches the enthalpy predicted from the difference in literature solution BDEs. A brief evaluation of the literature thermochemistry of TEMPOH and (t)Bu(3)PhOH supports the common assumption that DeltaS(o)(HAT) approximately 0 for HAT reactions of organic and small gas-phase molecules. However, this assumption does not hold for transition metal based HAT reactions. The trend in magnitude of |DeltaS(o)(HAT)| for reactions with TEMPO, Ru(II)(acac)(2)(py-imH) << [Fe(II)(H(2)bip)(3)](2+) = [Fe(II)(H(2)bim)(3)](2+) < [Co(II)(H(2)bim)(3)](2+), is surprisingly well predicted by the trends for electron transfer half-reaction entropies, DeltaS(o)(ET), in aprotic solvents. This is because both DeltaS(o)(ET) and DeltaS(o)(HAT) have substantial contributions from vibrational entropy, which varies significantly with the metal center involved. The close connection between DeltaS(o)(HAT) and DeltaS(o)(ET) provides an important link between these two fields and provides a starting point from which to predict which HAT systems will have important ground-state entropy effects.

A solid grasp of basic concepts and their relationships can stimulate learning motivation, improve teaching quality, and help students to build a body of knowledge in a discipline. Most of the previous studies have considered one chemistry topic amongst many others. To date, no studies have been conducted to explore the conceptual structures of teachers and students based on chemical concepts. Experts, teachers, and students (N=2348) from three public universities and ten upper-secondary schools in China participated in the studies. In Study 1, personal interviews, material evaluation, and importance rating questionnaires were conducted to determine the core concepts. In Study 2, the multidimensional scaling (MDS) and cluster analysis (CA) were conducted to explore the conceptual structures of upper-secondary school teachers and students. Then the structural differences between high- and lowachieving students were compared. The results showed that the three-dimensional solutions were appropriate for the conceptual structures of teachers and students, respectively. The high-achieving students have a more scientific and organized conceptual structure than those of low-achieving students. This study is the first to explore core concepts and their structure with a large sample size, and the reliable results help students understand abstract chemical concepts and improve their interest in scientific disciplines in the future.

Purpose: The purpose of this study was to develop the augmented reality (AR) educational program combined with the instructional guidance for supportive learning, which enhanced the thinking process cooperative discussion and problem-solving skills in chemistry subject. Design/methodology/approach: The method used the quasi-experimental research design. Of the 45 students who attended this experiment, only 25 with low achievement qualified in operating the AR learning system of saponification and transesterification environment (ARLS-STE) system. Findings: These results confirmed that the AR educational program could have increased substantial benefits in improvements of students' knowledge and the ability of the thinking process for the participants with the lowest score. In semi-structured interviews, most of participants enjoyed manipulating the ARLS-STE system, which was realistic, motived and interesting for learning science subjects. Originality/value: The low-achieving students have often been known with a low learning capability, and they lack in developing constructional knowledge, despite being keen for learning. Regarding educational concerns for this population, providing orientated learning and supportive materials could increase their learning effects. Virtual worlds are an efficient learning tool in educational setting. The AR can offer visual concepts and physical interaction for students with low achievement in learning. Thus, this study investigates the acceptability of an educational program designed in the ARLS-STE, which involves the learning effects of academic knowledge and the capability of thinking process for students with low achievement. The ARLS-STE system was developed for this proposal, based upon the marker-based AR technologies combined with hands-on manipulation.

In the evolving landscape of higher education, challenges such as the COVID-19 pandemic have underscored the necessity for innovative teaching methodologies. These challenges have catalyzed the integration of technology into education, particularly in blended learning environments, to bolster self-regulated learning (SRL) and higher-order thinking skills (HOTS). However, increased autonomy in blended learning can lead to learning disruptions if issues are not promptly addressed. In this context, OpenAI's ChatGPT, known for its extensive knowledge base and immediate feedback capability, emerges as a significant educational resource. Nonetheless, there are concerns that students might become excessively dependent on such tools, potentially hindering their development of HOTS. To address these concerns, this study introduces the Guidance-based ChatGPT-assisted Learning Aid (GCLA). This approach modifies the use of ChatGPT in educational settings by encouraging students to attempt problem-solving independently before seeking ChatGPT assistance. When engaged, the GCLA provides guidance through hints rather than direct answers, fostering an environment conducive to the development of SRL and HOTS. A randomized controlled trial (RCT) was employed to examine the impact of the GCLA compared to traditional ChatGPT use in a foundational chemistry course within a blended learning setting. This study involved 61 undergraduate students from a university in Taiwan. The findings reveal that the GCLA enhances SRL, HOTS, and knowledge construction compared to traditional ChatGPT use. These results directly align with the research objective to improve learning outcomes through providing guidance rather than answers by ChatGPT. In conclusion, the introduction of the GCLA has not only facilitated more effective learning experiences in blended learning environments but also ensured that students engage more actively in their educational journey. The implications of this study highlight the potential of ChatGPT-based tools in enhancing the quality of higher education, particularly in fostering essential skills such as self-regulation and HOTS. Furthermore, this research offers insights regarding the more effective use of ChatGPT in education.

Specific to the topic of oxidation-reduction (redox), teachers are obligated by the discipline to prioritise symbolic traditions such as writing equations, documenting oxidation states, and describing changes (e.g., what undergoes oxidation/reduction). Although the chemistry education research community endorses connecting the vertices of Johnstone's triangle, how symbolic traditions undermine chemistry concept development, especially during lesson planning and teaching, is underexplored. To clarify this gap, we use the Mangle of Practice framework to unpack the clash between symbolic vs. particulate-focused instruction. We investigate teachers' (n = 3) co-planning and micro-teaching of a redox learning design at the VisChem Institute-2 using a narrative approach and video research methods. Our results show that the traditions of redox instruction are problematically entrenched in chemistry symbols. Mnemonics, the single replacement reaction scheme, and the written net ionic equation all constrain instruction focused on chemical mechanism and causality in various ways. We assert that the nature of redox knowledge in terms of what is worth teaching and learning must first be re-evaluated for reform-based efforts to succeed. Implications and suggestions for chemistry teaching and research at both secondary and tertiary levels are discussed.

A scaffolding-based mind tool was designed to allow teachers to easily create lesson plans for in-class gamified activities and to embed various scaffoldings in the lesson plan design. The purpose of this study was to investigate the learning outcomes of a scaffolding-based mind tool integrated with gamified learning activities applied to a science course. The study was conducted to investigate students' learning outcomes, flow, and qualitative feedback on the scaffolding-based mind tool. A total of 134 high school students participated in the experiment. The results showed that the gamified activity with the scaffolding-based mindtool significantly improved students' learning effectiveness, but the learning effectiveness did not differ significantly from that of the students in the lecture-based instruction. In addition, the study found that the learners' flow was high, the students were engaged in the activity. The qualitative feedback analysis also revealed high positive evaluations of the usefulness of the gamified activity, mind tool, and scaffolds. In addition, students with low prior knowledge or low learning effectiveness had significantly higher active engagement in flow than those with high prior knowledge/learning effectiveness.

The impact of self-regulated learning (SRL) on students' performance in various subjects has been extensively studied. However, there has been limited research on how task-specific SRL skills and self-reported SRL skills affect students' learning outcomes in chemistry classes at senior secondary schools. To address this gap, we examined the task-specific SRL skills, self-reported SRL skills, and learning outcomes of a group of Grade 10 students (n = 170) studying the topic: Changes of Charged Electrolyte Solutions. Data was collected through a self-report SRL skills survey, a task-specific SRL skills survey, and an achievement test, and a path analysis was conducted to explore the relationship and effects between SRL skills and learning outcomes. Our findings revealed a direct relationship between students' task-specific SRL skills and their chemistry achievement. The clustering analysis showed that a significant number of students had SRL skills at the middle level in chemistry learning. Additionally, students with different SRL levels performed differently at specific SRL phases and strategies. These findings have important implications for teaching strategies aimed at promoting students' SRL and for the assessment of SRL in science education.

Despite years of research and practice inspired by chemistry education research, a recent report shows that US secondary instruction is not aligned with current national reform-based efforts. One means to mitigate this discrepancy is focusing on pedagogical conceptual change, its precursors (higher selfefficacy and pedagogical discontentment), and the subtleties of its mechanisms (assimilation and accommodation). In this study, we investigate the final reflections of participants (N = 35) who completed our professional development program known as the VisChem Institute (VCI). Our results show that Johnstone's triangle as well as evidence, explanations, and models can be conducive for stimulating pedagogical discontentment among VCI teachers who exhibit higher self-efficacy. In addition, how VCI teachers assimilate and/or accommodate reform-based chemistry teaching ideas problematizes conventional assumptions, broadens application of novel theories, and is germane to introductory chemistry learning environments across the world. Implications and recommendations for chemistry instruction and research at both secondary and tertiary levels are discussed.

Errors are natural elements of the learning process and provide a high potential to promote students' learning outcomes. In recent years, there has been much research about learning from errors. However, we know little about the relationship between students' error beliefs in chemistry and chemistry learning outcomes at present. Thus, the aim of this study was to explore the mechanisms of chemistry behavioral and cognitive engagements, adaptive reactions towards errors in chemistry and error beliefs in chemistry, and offer suggestions to the improvement of students' chemistry learning outcomes. We assessed all variables in eight different schools in China (N = 1352 students, Grade 10) and used structural equation modelling (SEM) to check the direct and indirect relationships between four variables. Our findings revealed that (1) chemistry behavioral and cognitive engagements, adaptive reactions towards errors in chemistry and error beliefs in chemistry significantly positively predicted students' chemistry learning outcomes; (2) both (a) adaptive reactions towards errors in chemistry and (b) chemistry behavioral and cognitive engagements acted as significant mediators between error beliefs in chemistry and chemistry learning outcomes; (3) the chain mediating effect of error beliefs in chemistry [right arrow] adaptive reactions towards errors in chemistry [right arrow] chemistry behavioral and cognitive engagements [right arrow] chemistry learning outcomes was significant. Finally, we discussed the important findings, pointed out the educational implications, acknowledged our study's limitations and suggested directions for future study.

Instructors in STEM classrooms often frame students' interactions with technologies to help them learn content. For instance, in many STEM domains, instructors commonly help students translate physical 3D models into 2D drawings by prompting them to focus on (a) orienting physical 3D models and (b) generating 2D drawings. We investigate whether framing prompts that target either of these practices enhance the effectiveness of an educational technology that supports collaborative translation among multiple representations. To this end, we conducted a quasi-experiment with 565 undergraduate chemistry students. All students collaboratively built physical 3D models of molecules and translated them into 2D drawings. In a business-as-usual "control" condition, students drew on paper, without support from an educational technology. In two experimental conditions, students drew in an educational technology that provided feedback and prompted collaboration. One condition received framing prompts to focus on physical models ("model" condition); another received prompts to generate intermediary drawings on paper ("draw" condition). Compared to the control condition, the model condition showed higher learning gains, but the draw condition showed lower learning gains. Analyses of log data showed that students made more model-based errors, and the prompts in the model condition reduced these model-based errors. However, interviews with instructors showed that they prefer drawing-focused prompts, in contrast to our results. These findings offer theoretical insights into how students learn to translate among representations. Furthermore, they yield practical recommendations for the use of educational technologies that support learning with multiple representations.

The questions in the practice assignments given to students in the form of worksheets or other formats are often grouped by chapter, topic, or concepts. There is a great emphasis on categorization. Most of the end-of-chapter problems in chemistry textbooks are organized by sections. Although this was done with the intention of helping students navigate the assignments more easily and practice in order, it is not what they are expected to do during the tests. There is a mismatch between what they practice on and how they are tested. The goal of this study is to examine the influence of the structure of the assignments on students' problem-solving performances. Two groups of students from chemistry classes were recruited to participate in this study. Each group had the same length of practice and identical questions with only one difference. The experimental group had assignments with mixed organization of questions, while the control group had traditional assignments with the questions organized around chapters and topics. Students completed three two-hour long problem-solving sessions during the weekends. Evaluation of their progress consisted of their solutions obtained from one pre-test and three post-tests, with one given after each problem-solving session. The study revealed that students in the experimental group increased their problem-solving success more than those in the control group starting from the first intervention. The achievement gap widened as the study progressed. It is recommended that educators and textbook publishers create and utilize assignments that contain more mixed questions on different topics and chapters.

Researchers have typically identified and characterized teachers' knowledge bases (e.g., pedagogical content knowledge and subject matter knowledge) in an effort to improve enacted instructional strategies. As shown by the Refined Consensus Model (RCM), understanding teacher learning, beliefs, and practices is predicated on the interconnections of such knowledge bases. However, lesson planning (defined as the transformation of subject matter knowledge to enacted pedagogical content knowledge) remains underexplored despite its central position in the RCM. We aim to address this gap by developing a conceptual framework known as Pedagogical Chemistry Sensemaking (PedChemSense). PedChemSense theoretically expands upon the RCM that generates actionable guidelines to support chemsistry teachers' lesson planning. We incorporate the constructs of sensemaking, Johnstone's triangle, and the models for perspective to provide a lesson-planning mechanism that is specific, accessible, and practical, respectively. Lesson examples from our own professional development contexts, the VisChem Institute, demonstrate the efficacy of PedChemSense. By leveraging teachers' sensemaking of the limitations and utility of models, PedChemSense facilitates teachers' designing for opportunities to advance their students' chemistry conceptual understanding. Implications and recommendations for chemistry instruction and research at secondary and undergraduate levels are discussed.

The Next Generation Science Standards (NGSS) have been imperative for informing many facets of the chemistry education research field, one of which includes the professional development (PD) of high school teachers. While many researchers and practitioners have responded to the NGSS' calls for reform by attending to internal factors that influence the PD's design, resources, and facilitation, there is less attention on extant factors that may negatively affect PD uptake and fidelity. Such factors encompass traditions of teaching chemistry or chemistry-related imprecisions within the NGSS themselves. If left unaddressed, these factors can act as anchors preventing advancements toward students' particle-level explanations and their chemistry conceptual understanding. In this article, we investigate the uptake and fidelity of our own PD program known as the VisChem Institute. The data are comprised of PD participants' learning designs (i.e., lesson plans) collected from the 2020 cohort (N = 20) and the 2021 cohort (N = 15). Results show that, although there was uptake in terms of the particulate level among participants' learning designs, more detail was ascribed to the description of molecular-level species rather than the explanation of relevant processes. Furthermore, an ontological analysis revealed that interpretations of evidence and models for description as well as symbolic heuristics for explanation may account for the VisChem approach's distortion in its translation to participants' learning designs. Implications and recommendations for chemistry instruction and research at both secondary and undergraduate levels are discussed.

This essay assessed the chemical safety knowledge of students in the School of Chemistry and Chemical Engineering, Tianjin University of Technology, concerning chemical storage, heat operation, waste disposal, and emergency response. The results show that students' familiarity and understanding of safety knowledge is not satisfactory, especially in the waste disposal and emergency response. In addition, the significant difference is also found among different subgroups (gender, major, and academic year). Therefore, in the following work, the analytical experimental courses incorporate online and offline safety education into the teaching design for first-year undergraduates. Prudent and continuous safety training is expected to be routinely provided for all undergraduates and postgraduates in the future.

In the wake of the ongoing nationwide antiracist movement, the academy at large has been reflecting on its role in society and the pursuit of social justice. Here, we examine the state of diversity, equity, and inclusion (DEI) in chemistry education research and practice through a literature review and offer suggestions for future directions. Through a keyword search in four leading journals in chemistry and science education, we chose to review 73 articles with DEI-relevant research foci. Through quantitative analysis, we noticed that there has been a recent increase in DEI-focused studies and that most studies have been conducted at precollege and college levels. We also performed qualitative analysis in order to identify common themes across reviewed articles. On the basis of this analysis, we organized our findings into four sections: the rationale for advancing DEI, the current state of DEI, prevalent explanations of existing inequities, and strategies for advancing DEI. The literature indicates that the state of DEI has improved considerably over the years, particularly in terms of the numbers and achievements of women and historically minoritized groups. These improvements may be driven by widespread research in and embracement of novel pedagogical approaches that enhance students' academic outcomes and classroom culture. However, we also noticed areas with scope for improvement. We make suggestions to continue this hard-won progress: expanding research in less studied contexts, holistic reform approaches across institutional levels, and justice- and relevance-oriented curricular reforms. We also urge the Chemistry Education Research (CER) community to reconceptualize frameworks for equity and diversity to move beyond increasing the numbers of people from minoritized groups.

Introductory chemistry textbooks often present valence bond (VB) theory as useful, but incorrect and inferior to molecular orbital (MO) theory, citing the electronic structure of O[subscript 2] and electron delocalization as evidence. Even texts that initially present the two theories on equal footing use language that biases students toward the MO approach. However, these "failures" of VB are really just misconceptions and/or misapplications of the theory. At their theoretical limits, both VB and MO are equivalent; they simply approach that limit from different sides. Certain concepts may be easier to grasp with one theory or the other so that having a commanding knowledge of both is extremely beneficial. However, presenting one theory as superior to the other suppresses the ability to look at a problem from both sides and is therefore detrimental to students and the whole of chemistry. It is time for VB and MO to be taught on equal footing like the complementary theories they are.

In response to the COVID-19 pandemic, many colleges and universities transitioned their face-to-face courses to emergency remote online courses during the spring of 2020. This study, conducted at a large, urban, diverse public university in the United States, answers the questions of how the sudden switch to emergency remote online instruction and the encompassing events of the pandemic changed student learning and engagement in a college-level introductory chemistry course. The research addresses the demographic and lifestyle factors that determine the magnitude of these changes. The mixed-methods approach uses a 19-item Pandemic Online Student Engagement (POSE) scale to quantitatively evaluate changes in student engagement and combines it with a qualitative analysis of student essay responses. The results reveal a decrease in student engagement, with underrepresented people of color (URPOC) students particularly affected and reporting significantly greater decreases in three of the four engagement components: skills engagement, participation engagement, and performance engagement. The decreases in motivation and self-regulation occurred in part because the historic pandemic event made it more difficult to focus on studies, and because students' home environments were not conducive to self-regulated learning. This study provides unique insights for chemistry instructors and college administrators into how the sudden changes in instructional dynamics affected students while the pandemic unfolded. Studies like this are necessary to prevent widening achievement gaps if the current pandemic lingers or if future threats dictate another widespread adoption of emergency remote online learning in general chemistry.

Implementation of the flipped classroom approach into STEM courses has been popularized in the last decade and has generally been reported to improve student performance outcomes. In a flipped classroom setting, students typically first encounter course content in the online format and subsequently engage in some form of active learning during the in-person class meetings. Although the flipped classroom approach can promote increased student engagement and provide an opportunity to apply content encountered in the classroom, this structure does not generally give students opportunities for discrete concept development prior to the application phase of learning. In an effort to build concept development activities into a flipped classroom structure, five learning cycle activities were implemented in a large enrollment first-term general chemistry course that has previously implemented the flipped classroom design. Four of these learning cycle activities incorporated PhET simulations as part of the exploration phase of learning, and all five activities were facilitated during the in-person class meetings to initiate the learning cycle. The activities were designed to help students explore models and engage in concept development. The application phase of the learning cycle was facilitated by flipped classroom modules or in-person classroom activities that included whole-class questioning coupled with collaborative think-pair-share discussion. Performance gains in conceptual understanding were evaluated by employing a one-group, pre-post-post research design. Non-parametric Friedman's tests indicate a significant main effect across time for each concept development activity, and post hoc Wilcoxon signed rank tests indicate the post-test and final exam scores are significantly higher than the pre-test scores for each activity (p < 0.001 for each pre-post and pre-final pairwise comparison). The findings reported herein demonstrate that concept development activities can be successfully integrated with flipped classroom modules and the combination of the introductory learning cycle activities and flipped classroom application activities led to knowledge gains that persisted through the end of the course. In total, creating this type of blended learning environment appears to help students achieve understanding of core general chemistry concepts.

COVID-19 has thrust educators into a period of uncertainty, complicating conventional ways of teaching and learning. We suspect that the pandemic has magnified the challenges that some high school teachers already experience, particularly when they are the sole chemistry teacher at their school. The pandemic has likely inhibited collegial interactions and access to professional development (PD). Our reflections from redesigning a face-to-face PD program to one that is remotely delivered provide recommendations that advance PD accessibility and interactivity to mitigate isolation and other longstanding challenges teachers may face. In this article, we discuss how the cognitive learning model informed emergent teaching practices that guided the transformation of the PD's implementation for 20 high school chemistry teachers. Our reflections on the PD's strengths, areas for improvement, and insights alongside participant feedback provide enduring guidelines for fellow teacher educators. Specifically, we forward the importance of conceptualizing theory-informed design principles first, and then modifying the delivery with appropriate tools and technologies. As PD facilitators, we also draw attention to the necessity for flexibility. Remaining open to adaptation during implementation is crucial to advance teacher learning and engagement. We hope our process for how and why our PD program was redesigned will inspire future teacher educators to explore new, postpandemic ways of maximizing high-quality PD experiences.

Chemistry is a subject which involves a number of abstract concepts, making it a difficult and frustrating learning process for many students. Educators and researchers believe that technology could provide an opportunity to address this problem. However, it is challenging to find a model for appropriately and successfully integrating technology into chemistry education. Therefore, in this study, a review was conducted on the technology-enhanced chemistry learning studies published in Social Science Citation Index (SSCI) journals from 2010 to 2019. This study searched the target articles from the Web of Science (WOS) database and excluded those studies that did not adopt a comparative research design. Finally, 60 studies were included in this research trend analysis. A coding scheme was developed for the types of technology, the types of learning tools, the roles of technology in chemistry learning, learning topics, learning environments, participants, research designs, and the learning outcomes the researchers evaluated. From the analysis results, it was found that (1) inorganic chemistry and physical chemistry courses were the main learning topics, while the formal classroom was most often referred to as the research setting. The most frequently discussed issue was students' learning achievement. (2) Regarding technology integration, offering students learning content through personal computers was the main activity mode. The technology was used for lower-level implementation, that is, providing supplementary materials for students. (3) Finally, using keyword analysis, it is possible to extract the recent concerns of the researchers, and from the results of the study, it is clear that the researchers are placing increasing emphasis on learners' experience and skill development in the learning process. Accordingly, this study highlights the features of the research trends and then provides suggestions for researchers in the technology-enhanced chemistry learning field.

The purpose of this study is to examine the effects of different ways to use visualizations on high school students' electrochemistry conceptual understanding and motivation towards chemistry learning. Expanding upon a model-based learning approach (Khan, 2007), we adopted a VGEM sequence (View, Generate, Evaluate, and Modify) to create three instructional conditions. All conditions involved the viewing, evaluating, and modifying phases, whereas there were variations in the generating phase: (1) finishing worksheets (V group), (2) generating drawings (VD group), and (3) generating animations (VA group). Three intact classes with 109 eleventh graders from a public high school were randomly assigned to the three groups. A test of conceptual understanding was used as the pretest, posttest, and delayed posttest to assess respectively initial understanding, changes, and retention of understanding up to 6 weeks later. A questionnaire to measure students' motivation to learn chemistry was administered before and after the instruction. Statistical results of the within-group comparisons revealed that all three instructional conditions could support students to develop a significantly better conceptual understanding of electrochemistry and that in the three groups, students' understanding was retained after 6 weeks. Regarding the overall motivation before and after the instruction, only the VA group showed motivational benefits for chemistry learning. Furthermore, the between-group comparisons indicated no significant differences between the means of the three groups in the posttest and delayed posttest, and suggested that the three groups developed and retained a similar level of conceptual understanding after the instruction. Similarly, different uses of visualizations made no difference to students' chemistry learning motivation. This study advances the understanding of how to develop effective instructional activities with visualizations for chemistry learning, and suggests possible conceptual and motivational benefits of viewing and generating visualizations.

As an outcome of multidiscipline integration, the polymeric surfactant is of growing importance in modern industry and scientific research. However, the instructional introduction on polymeric surfactants is still insufficient in universities nowadays. In order to effectively guide undergraduates to study polymeric surfactant, a new polymeric surfactant, poly­(acrylic acid-"co"-octadecyl acrylate), was designed and synthesized by copolymerization between acrylic acid and octadecyl acrylate. Moreover, its surface activity and rheological performance were also analyzed by contact angle meter, laser scanning confocal microscope, polarizing microscope, and rotary rheometer. Generally, as a combination of the hands-on exercise with theoretical lecture, this laboratory experiment enabled students to understand the key concepts and chemical nature of polymeric surfactants in depth. In addition, the ability to incorporate multidiscipline concepts into the practical issues students must solve was also cultivated by this exercise.

Chemical screening libraries often feature natural product extracts (NPEs) due to the intriguing biological activities they possess and the structural diversity found in their individual components. A research project originally designed to create an extract library of every specimen in the University of Rhode Island (URI) Heber W. Youngken Jr. Medicinal Garden soon turned into a laboratory-based teaching project in which upper-division undergraduate students generated and analyzed extracts in an academic minisemester project. Additionally, motivated upper-division undergraduates carried out independent research isolating biologically active molecules. Hands-on laboratory activities enhanced students' knowledge of methodologies and workflows associated with extract analysis and biological evaluation of botanical extracts. The synergy of the laboratory course with the independent study contributed to workforce preparation and library generation.

Biocompatible and biodegradable block copolymers composed of poly(ethylene glycol) (PEG) and aliphatic polyester are a class of promising biomaterials. Herein, a teaching experiment was designed to furnish undergraduates with a reliable method to synthesize an amphiphilic poly([epsilon]-caprolactone)-PEG-poly([epsilon]-caprolactone) (PCL-PEG-PCL) triblock copolymer via ring-opening polymerization of [epsilon]-caprolactone using PEG as the macroinitiator and diphenyl phosphate as the green organocatalyst; the concentrated solution of synthetic polymer in water was then demonstrated as an injectable thermogel with a sol-gel transition upon heating. Ten students serving as volunteers successfully synthesized PCL-PEG-PCL copolymer, and then analyzed their specimens using various techniques including proton-nuclear magnetic resonance spectroscopy, gel permeation chromatography, differential scanning calorimetry, and X-ray diffraction and learned the principles of instruments. Finally, students prepared an aqueous polymer solution, and observed its interesting spontaneous physical gelation upon heating via the tube-inverting approach and dynamic rheological analysis. The experimental features captured the students' attention and made them more enthusiastic participants. This newly designed teaching experiment afforded senior undergraduates an excellent opportunity to consolidate basic concepts and principles in books with practical experimental sessions in the field of polymer chemistry, analytical chemistry, and materials science.

Instruction in most STEM domains uses visuals to illustrate complex problems. During problem solving, students often manipulate and construct visuals. Traditionally, students draw visuals on paper and receive delayed feedback from an instructor. Educational technologies have the advantage that they can provide immediate feedback on students' visuals. This feedback allows students to learn visualization conventions and to learn new content knowledge. This paper presents a design-based research approach to develop visual tools for an educational technology for chemistry. In this research, three design tradeoffs emerged: (1) Which aspects of the drawing task should visual tools constrain? (2) How should visual tools account for variability in students' prior experiences? (3) How should the design of multiple visual tools be aligned so that students can easily transition between them? Our design-based research approach comprises three studies that address each of these design challenges in the context of chemistry visualizations. Our studies yield principles for the design of interactive visual tools for educational technologies.

"Manga" are graphic novels that are considered to have the potential to effectively convey concepts and engage readers. The efficacy of "manga" has been validated for chemical safety education to students in three universities in Japan, Taiwan, and Thailand. Students were asked to examine a photo to identify hazards and hazardous behaviors that can potentially lead to accidents before and after reading a "manga" that explains the risk of fires and explosions. The identified hazards/hazardous behaviors were classified into seven categories, and the average number of hazards/hazardous behaviors was determined in each category. The differences before and after the lesson were analyzed to evaluate the effectiveness of "manga" as an educational tool. In the students' answers, in all three of the universities, some common features were observed: Subjects easily identified certain hazardous conditions in the photo, particularly noting deficient or unsuitable personal protective equipment. The hazards/hazardous behaviors that can potentially result in ignitions, fires, and explosions were more likely to be identified after the lesson. Many students found the "manga" a helpful tool for learning chemical safety.

Connection-making among multiple representations is a crucial but difficult competence in STEM learning. Prior research has focused on one type of learning process involved in connection-making: sense-making processes leading to conceptual understanding of connections. Yet, other research suggests that a second type of learning process is important: inductive learning processes leading to perceptual intuitions about connections. We investigate whether combining instructional activities designed to support sense-making processes for understanding of connections (understanding activities) and instructional activities that support inductive processes for perceptual intuitions about connections (perception activities) enhances students' learning of chemistry knowledge. A laboratory-based experiment with 117 undergraduate students compared students in (a) a control condition that received only conventional activities that did not require connection-making; (b) a condition that received conventional and understanding-activities; (c) a condition that received conventional and perception-activities; and (d) a combined condition that received conventional, understanding-activities, and perception-activities. Results show that only the combined condition outperformed the control condition on a test of chemistry knowledge. Eye-gaze data and verbal reports show that understanding-activities and perception-activities have complementary effects on how students integrate information from multiple representations during the learning phase. Finally, we found that students' spatial skills moderate their benefit from understanding-activities and perception-activities.

Abstract Layered bismuth (Bi) has been focused on two Peierls distortion derivatives, i.e., bulk stable β-phase (A7 phase), black phosphorus-like α-phase (A17 phase), and their mutated structures. Metastable structures beyond Peierls distortion system are yet rarely accessible. Here, Bi in square symmetry ( $${C}_{4v}$$ C 4 v ), called s-Bi, was grown via physical vapor deposition. The co-existence of three 120°-associated s-Bi crystal grains was analyzed using transmission electron microscopy. 120°-oriented one-dimensional (1D) nuclei indicate s-Bi heteroepitaxy on six-fold symmetric ( $${C}_{6v}$$ C 6 v ) mica (001). A subsequent nanorod-like nuclei coalescing could promote a morphology evolution, resulting in triangular or hexagonal nanosheets with the unique triple s-Bi structure suitable for later β-Bi growth. Lattice misfit and strain calculations suggest a supercell match between $$4\times 7$$ 4 × 7 s-Bi and $$3\times 3$$ 3 × 3 mica (001). This work demonstrates the metastable s-Bi structure via anisotropic heteroepitaxy of $${C}_{4v}$$ C 4 v s-Bi on $${C}_{6v}$$ C 6 v mica.

A public demonstration of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) for fast and sensitive qualitative elemental analysis of solid everyday objects is described. This demonstration served as a showcase model for modern instrumentation (and for elemental analysis, in particular) to the public. Several steps were made to adapt conventional laboratory-based ICP-MS instrumentation to bring it to the outreach event and also to improve ease-of-use, which helped facilitate discussion with attendees. Rather than the conventional closed-cell design, this setup consisted of a laser ablation (LA) system that allowed for ablation in ambient conditions which enabled swift sample exchange during the demonstration. A gas exchange device was operated between the LA system and the ICP-MS instrument allowing for the replacement of ambient gases with argon. This particular setup was utilized during an open day event to demonstrate how LA-ICPMS can be used for qualitative analysis of major and trace elemental components in objects. In particular, visitors were encouraged to present objects for elemental analysis. Complete elemental analysis of supplied samples such as keys, coins, rings, and necklaces was demonstrated by recording full mass spectra. Variation of the elemental composition across different regions of objects was shown by scanning the laser beam and acquiring transient elemental signals.

The reaction process of copper-aluminum displacement in agar gel was observed at the microscopic level with a stereomicroscope; pine-like branches of copper crystals growing from aluminum surface into gel at a constant rate were observed. Students were asked to make hypotheses on the pattern formation and design new research approaches to prove their hypotheses. Results of the experiments designed by students well proved the existence of microcells in reaction system, which caused continuous growth of copper branches. The whole experimental teaching process motivated students by stimulating their interest and enthusiasm.

Variability in the stratosphere, especially extreme events such as sudden stratospheric warmings (SSWs), can impact surface weather. Understanding stratospheric prediction uncertainty is therefore crucial for skillful surface weather forecasts on weekly to monthly timescales. Using ECMWF subseasonal hindcasts, this study finds that stratospheric uncertainty is most strongly linked to tropospheric uncertainty over the North Pacific and Northern Europe, regions that can modulate but also respond to stratospheric variability, suggesting a two-way propagation of uncertainty. A case study of the 2018 SSW event shows an initial poleward and upward propagation of uncertainty from tropical convection, followed by a downward propagation where ensemble members that accurately predict the SSW are also better at predicting its downward impacts. These findings highlight the locations in the troposphere that are linked to stratospheric uncertainty and suggest that improved model representation of tropospheric mechanisms linked to polar vortex variability could enhance both stratospheric and extratropical surface prediction.

The influence of nonmigrating diurnal tides on Na layer variability in the mesosphere and lower thermosphere regions is investigated for the first time using data from the Optical Spectrograph and InfraRed Imaging System (OSIRIS) on the Odin satellite and Specified Dynamics Whole Atmosphere Community Climate Model (SD-WACCM) with metal chemistry. The Na density from OSIRIS exhibits a clear longitudinal variation indicative of the presence of tidal components. Similar variability is seen in the SD-WACCM result. Analysis shows a significant relationship between the nonmigrating diurnal tides in Na density and the corresponding temperature tidal signal. Below 90 km, the three nonmigrating diurnal tidal components in Na density show a significant positive correlation with the temperature tides. Conversely, the phase mainly indicates a negative correlation above 95 km. Around the metal layer peak, the response of the Na density to a 1 K change in tidal temperature is estimated to be 120 cm−3.

Medium-temperature anaerobic digestion experiments lasting for 55 days were conducted using sulfamethoxazole (SMX)-containing chicken manure in sequential batch reactors added with nano-Fe2O3 at a concentration of 300 mg·kg−1·TS or nano-C60 at a concentration of 100 mg·kg−1·TS. The effects of nanoparticles on the anaerobic digestion properties of SMX-containing chicken manure were assessed by measuring the following indicators: biogas production by anaerobic digestion, chemical parameters, enzyme concentrations, and bacterial diversity and changes in antibiotic concentrations over time. The law of bacterial degradation of SMX was analyzed. The results showed that (1) adding either nano-Fe2O3 or nano-C60 promoted biogas production by anaerobic production from chicken manure containing different concentrations of SMX, and the cumulative biogas production in Fe2O3 and nano-C60 increased by 35.4% and 130.7%, respectively. The final cumulative biogas productions in different groups were as follows: 3,712(CK), 4,281(S1), 3,968(S2), 4,061(S3), 4,498(S4), and 4,639(S5) mL and the final concentration of SMX residues varied between 99.79% and 99.94%; (2) Bacterial abundance at the phylum level: on day 1, Firmicutes and Bacteroidota were the main dominant bacterial phyla, with relative abundances of 45.13–68.53% and 26.12–48.32%, respectively. The addition of nanoparticles increased the abundance of Bacteroidota in S4 and S5 significantly. The abundance of Bacteroidota was slightly higher in the group added with nanoparticles than in S2. On day 50, Firmicutes became the dominant bacterial phylum, and its relative abundance varied little across the groups, ranging from 90.87% to 94.54%; (3) At different stages, the bacterial community structure at the genus level was dramatically affected by substrates. As nutrients were being depleted, some bacterial communities lost their original competitive advantages. On day 5, the relative abundance of Prevotella increased. Especially, the relative abundances of Prevotella in S4 and S5 added with nanoparticles were lower than that in S2 by 8–10%. On day 15, the relative abundance of Prevotella in S2 decreased compared with the control group CK. A decrease was also observed in S4 and S5, although to a smaller extent than in S2.

Terahertz (THz) computed tomography (THz CT) exhibits the potential to provide a wealth of data, surpassing that of THz tomographic imaging in applications such as detecting embedded defects, particularly defect evolution within a glass fiber-reinforced polymer. To realize high-resolution THz CT, a systematic approach guided by wave propagation simulation was employed. First, the front wave of the THz beam was fine-tuned to realize a beam diameter of