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In recent years, chemistry educators are increasingly adopting immersive virtual reality (IVR) technology to help learners visualise molecular interactions. However, educational studies on IVR mostly investigated its usability and user perceptions leaving out its impact on improving conceptual understanding. If they evaluated students’ knowledge gains, they tended to use information recall tests to assess knowledge gains. Employing interviews and diagram-drawing tasks, this study explored how students’ conceptual understanding of the nature of hydrogen bonds and the shape of snowflakes changed through a collaborative IVR experience on snowflakes. Participants were 68 undergraduate chemistry students. Videos of pre-/post-interviews and student-generated diagrams were analysed. The results indicated a marked improvement in students’ conceptual understanding of the nature of hydrogen bonds among water molecules in snowflakes. After IVR, 57 students provided scientifically acceptable explanations of the nature of hydrogen bonds. Improvements in students’ understanding were related to the intermolecular nature of hydrogen bonds, the role of lone pairs of electrons in forming hydrogen bonds, and molecular interactions in 3D space. This study suggests that collaborative IVR could be a powerful way for students to visualise molecular interactions, examine their alternative conceptions, and build more coherent understanding. Implications for the design and implementation of IVR activities for science learning are discussed.

Recent studies have reported a growing trend of using student-generated diagrams for assessment in science teaching and research. However, many educators tend to use diagrams to explore students’ perceptions of scientists and their work rather than explore conceptual understanding of abstract concepts. In this study, we used diagrams to investigate students’ conceptual understanding of the nature of hydrogen bonds among water molecules in snowflakes. Participants were 70 first- and second-year university students. Following a sequence of interview prompts, the students drew diagrams to illustrate the interactions amongst water molecules in snowflakes. Sixty students’ diagrams were analyzed inductively using a constant comparison method. Most diagrams showed that the students did not have major challenges drawing the water molecule structure, recognizing polarity of a water molecule, or recognizing the intermolecular nature of hydrogen bonds. However, the diagrams revealed varied ways in which students conceptualized the formation of hydrogen bonds. A third of the diagrams revealed students’ alternative conceptions about the role of lone pairs of electrons in the formation of hydrogen bonds. Most diagrams which showed a good understanding of the nature of a hydrogen bond revealed students’ difficulties in recognizing molecular interactions in a 3D space. Our findings suggest that student-generated diagrams can provide a powerful way to understand students’ conceptions of abstract science concepts.

The COVID-19 pandemic has fundamentally changed many aspects of our world including the way we teach chemistry. Our emergence from the pandemic provides an opportunity for deep reflection and inten...

Immersive Virtual Reality (VR) is increasingly being used as an educational tool to help students visualise complex structures and phenomena. The use of VR is particularly useful for science animation that involves sub-microscopic and abstract processes in a 3D environment, such as the interactions of molecules, electrons and forces. However, few research studies have explored how immersive VR can support science visualisation compared to existing tools, notably computer animation on a flat screen. The study in this chapter used a semiotic perspective to examine the multimodal affordances of a ‘virtual’ mode of representation made possible by VR technology. The study involved the design and development of a VR animation to show the structure and reaction of an enzyme called acetylcholinesterase. A group of chemistry undergraduates was recruited to take part in a learning activity using the VR animation in pairs. Based on an analysis of the learners interacting with the VR animation, this chapter reports on the affordances of VR compared to other tools in five specific areas: viewing, sequencing, modelling, scaling and manipulating. Through the use of case studies, it also illustrates and discusses how these affordances facilitate student learning of molecular interactions.

A multi-institution collaborative team of Australian chemistry education researchers, teaching a total of over 3000 first year chemistry students annually, has explored a tool for diagnosing students' prior conceptions as they enter tertiary chemistry courses. Five core topics were selected and clusters of diagnostic items were assembled linking related concepts in each topic together. An ordered multiple choice assessment strategy was adopted to enable provision of formative feedback to students through combination of the specific distractors that they chose. Concept items were either sourced from existing research instruments or developed by the project team. The outcome is a diagnostic tool consisting of five topic clusters of five concept items that has been delivered in large introductory chemistry classes at five Australian institutions. Statistical analysis of data has enabled exploration of the composition and validity of the instrument including a comparison between delivery of the complete 25 item instrument with subsets of five items, clustered by topic. This analysis revealed that most items retained their validity when delivered in small clusters. Tensions between the assembly, validation and delivery of diagnostic instruments for the purposes of acquiring robust psychometric research data versus their pragmatic use are considered in this study.

Computer-aided visualisation has played an essential role in helping students construct a better understanding of molecular interactions over the years. However, students still need to translate 2D images on a screen into 3D molecular structures in their minds, and they often find it challenging to develop a clear mental picture of complex molecules. As an alternative platform for molecular visualisation, immersive virtual reality (VR) holds great promise for addressing students’ difficulties. To examine the educational possibilities and limitations of immersive VR environments, we adopted a design research approach. We developed a series of learning activities to teach students about an enzyme and its interactions with substrates and then conducted a user study in an immersive VR environment. Twenty-two first-year university chemistry students participated in the user study. Their VR sessions along with pre- and post-interviews were video-recorded and later analysed to understand how various features of the immersive VR activities supported and impeded students’ conceptual understanding and their ability to visualise molecules. Future research directions and the implications for chemistry teaching are discussed.

Students entering tertiary studies possess a diverse range of prior experiences in their academic preparation for tertiary chemistry so academics need tools to enable them to respond to issues in diversity in conceptual models possessed by entering students. Concept inventories can be used to provide formative feedback to help students identify concepts that they need to address to improve construction of subsequent understanding enabling their learning.Modular, formative learning activities that can be administered inside or outside of class in first year chemistry courses have been developed. These activities address key missing and mis-conceptions possessed by incoming student. Engagement in these learning activities by students and academics will help shift the culture of diagnostic and formative assessment within the tertiary context and address issues around the secondary/tertiary transition. This diagnostic/intervention framework is currently being trialed across five Australian tertiary institutions encompassing a large heterogeneous sample of students.

The changing role of professions in society is one of the key themes in literature about the professions. In his systems interpretation of the professions Abbot (1988) presented the professions as growing, joining, splitting, adapting and dying.

The focus of this chapter is the challenge of portraying molecular-level structures and processes in visualisations to help novices develop useful mental models of the molecular world for a deep understanding of chemistry. The challenge is to judiciously balance the demands of scientific accuracy with the pedagogical demands of clear communication and avoidance of cognitive overload. The advantages and disadvantages of scripted animations and calculated simulations are compared, resulting in the recommendation that both are required to visualize this level for educational purposes. Great care is required in deciding what species (spectator ions? solvent molecules?) should be omitted for simplification to decrease cognitive load.

A prior study showed that students best make predictions about the outcome of opening a valve between two flasks containing a fluid or vacuum when they view both a demonstration video and a particulate animation, but the study showed no influence from the order in which these visualizations were used. The purpose of this current research was to study the effect of the order of visualization on students’ particulate-level explanations. For this study, first-year general chemistry students in a south-central university in the United States were asked to choose, or type in their own explanations, for three experiments involving diffusion–effusion. Student ability to focus on particulate explanations was investigated after viewing either a macroscopic demonstration or an animated particle view. Students were directed to a Web site where they received one of two randomly assigned treatments. One group of students was shown the particulate animation first, followed by the macroscopic demonstration. For the othe...

Most chemistry teaching operates at the macro (or laboratory) level and the symbolic level, but we know that many misconceptions in chemistry stem from an inability to visualise structures and processes at the sub-micro (or molecular) level. However, one cannot change a student’s mental model of this level by simply showing them a different, albeit better, model in an animation. Molecular-level animations can be compelling and effective learning resources, but they must be designed and presented with great care to encourage students to focus on the intended ‘key features’, and to avoid generating or reinforcing misconceptions. One misconception often generated is the perception of ‘directed intent’ in processes at the molecular level, resulting from the technical imperative to minimise file size for web delivery of animations. An audiovisual information-processing model – based on a combination of evidence-based models developed by Johnstone and Mayer, cognitive load theory, and dual-coding theory – has been used to inform teaching practice with animations, and seed questions for research on student attributes affecting development of mental models using animations. Based on this model, the constructivist VisChem Learning Design probes students’ mental models of a substance or reaction at the molecular level before showing animations portraying the phenomenon. Opportunities to apply their refined models to new situations are critical. [Chem. Educ. Res. Pract., 2006, 7 (2), 141-159]

Different visualization techniques have been used for teaching chemistry concepts. Previous studies have shown that when molecular animations and video demonstrations are used, students seem to better correlate all three levels of representation: macroscopic, submicroscopic, and symbolic. This thinking process allows the students to improve their conceptual understanding and ability to create dynamic mental models. In this study, general chemistry students viewed three experiments involving dynamic fluid equilibrium in a graphic design, a video demonstration, and a molecular animation. The study investigated whether video demonstrations or particulate animations helped the students' conceptual understanding, and if the order of visualizations (video or animation first) produced any differences. Students showed improvement after each visualization. Surprisingly, there was significant improvement in responses between the first and second visualization. This work shows the importance of combining both types of visualizations, but it does not indicate a preference toward a specific order.

A deep understanding of chemistry requires internal visualization of structures and processes at the molecular level to rationalize observable chemical and physical properties, and make sense of chemistry symbolism and mathematical relationships. The paper argues that accurate mental models of the molecular world are needed to address the student misconceptions described in the literature, and describes the potential and limitations of the VisChem animations to develop useful mental models. A constructivist learning design has been developed and evaluated as a best-practice strategy for effectively using the VisChem resources for learning. This communication summarizes one of the invited papers to the Interactive Visualizations for Chemistry Teaching and Learning ACS CHED Committee on Computers in Chemical Education online ConfChem held from May 8 to June 4, 2015. The lively discussions that followed addressed the difficulty of showing the crucial role of ion hydration without producing cognitive overload...

The research literature clearly indicates that many student misconceptions in chemistry stem from an inability to visualize structures and processes at the molecular level. A selection of these misconceptions was targeted in the VisChem project by producing a suite of molecular-level animations. The animations were produced with care to balance the often-competing demands of scientific accuracy, technical constraints, and clarity of communication.

En general on obtient de bonnes separations des isomeres Δ-S et ∧-S du 1er et α,β 1 -RS,SR, β 1 -RR,SS, β 2 -RS,SR et β 2 -RR,SS du dernier

The reversed-phase high-performance liquid chromatography of a variety of [Co(NH 3 ) 5 X] 2+ cations including halo (X  F − , Cl − , Br − , I − ), isomeric anionato (X  ONO − , NO 2 − ; NCS − , SCN − ), anionato (X  NO 2 − , NO 3 − , N3 − , Cl − ), carboxylato (X  CH 3 C0 2 − , CF 3 C0 2 − , C 2 ,H 5 CO 2 − , C 3 H 7 C0 2 − ), isomeric toluato (X  CH 3 C 6 H 4 CO 2 − ), some [Co(NH 3 ) 5 X] 3+ cations (X  H 2 O, (CH 3 ) 2 SO, NH 3 ) and [Co(en) 3 ] 3+ are reported. In general good separations are achieved using 25 m M toluenesulphonate ion-pairing reagent in water-methanol (isocratic or gradient) using a μBondapak C 18 column. The efficiency and speed of the separations are superior to those obtained by ion-exchange chromatography.

Behandlung der Co-Aminosaure-Komplexe (I) mit dem Trifluormethansulfonat (II) gibt die Co(III)-Aminosaureester (III), von denen (IIIa) durch Kupplung mit entsprechenden Aminosaureestern (IV) zu den Dipeptid-Komplexen (V) umgesetzt werden.

En general on obtient de bonnes separations des isomeres Δ-S et ∧-S du 1er et α,β 1 -RS,SR, β 1 -RR,SS, β 2 -RS,SR et β 2 -RR,SS du dernier