Students’ understanding of mathematical expressions in physical chemistry contexts: an analysis using Sherin’s symbolic forms

Undergraduate physical chemistry courses require students to be proficient in calculus in order to develop an understanding of thermodynamics concepts. Here we present the findings of a study that examines student understanding of mathematical expressions, including partial derivative expressions, in two undergraduate physical chemistry courses. Students participated in think-aloud interviews and responded to a set of questions involving mixed second partial derivatives with either abstract symbols or thermodynamic variables. The findings describe students' ability to transfer mathematics knowledge to chemistry problems and how students use symbolic forms described b

Analysis of inquiry materials to explain complexity of chemical reasoning in physical chemistry students’ argumentation

One aim of inquiry activities in science education is to promote students’ participation in the practices used to build scientific knowledge by providing opportunities to engage in scientific discourse. However, many factors influence the actual outcomes and effect on students’ learning when using inquiry materials. In this study, discourse from two physical chemistry classrooms using the Process‐Oriented Guided Inquiry Learning (POGIL) approach was analyzed using a lens of scientific argumentation. Analysis of the complexity of reasoning in students’ arguments using a learning progression on chemical thinking indicated that students did not employ very complex reasoning to construct arguments. To explain the distribution of reasoning observed, a separate analysis of the curricular materials was performed using the Task Analysis Guide for Science (TAGS). Results indicate a relationship between the task’s targeted scientific practice and how students used evidence in their arguments as well as between the task’s cognitive demand and the complexity of reasoning employed in arguments. Examples illustrating these relationships can be used to inform implications for design of inquiry materials, facilitation of classroom discourse, and future research. © 2017 Wiley Periodicals, Inc. J Res Sci Teach 10: 1322–1346, 2017Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139982/1/tea21407_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139982/2/tea21407.pd

Article Students' Understanding of External Representations of the Potassium Ion Channel Protein Part II: Structure-Function Relationships and Fragmented Knowledge*

Research that has focused on external representations in biochemistry has uncovered student difficulties in comprehending and interpreting external representations. This study focuses on students' understanding of three external representations (ribbon diagram, wireframe, and hydrophobic/hydrophilic) of the potassium ion channel protein. Analysis of the interview data demonstrates that students were able to use the ribbon structures and polarity of the cell membrane to help support claims about the protein's orientation and interactions within the cell membrane. Students expressed fragmented understandings of the interactions between the potassium ion and the aqueous solution outside/inside of the cell membrane. Suggestions for instruction are to probe student understanding to help students activate prior knowledge and to help them build a more connected set of concepts pertaining to protein structure and function. Keywords: Visual literacy, tertiary education, scholarship of teaching and learning. Biochemistry students must interpret and use external representations to understand large, complex biochemical macromolecules. Whereas our first article in this two-part series focused on how students interpret three types of external representations of the potassium ion channel, this article describes how students use external representations to support their claims about channel's structure and function. Schö nborn and Anderson [1] have identified factors that affect students' ability to interpret and use external representations in biochemistry, including: • Ability to make sense of and read the external representation • Ability to select and retrieve conceptual knowledge of relevance to the external representation • Understanding of the concepts of relevance to the external representation Schö nborn and Anderson Sampling and Participants Maximum variation sampling methods were used to capture the central themes that cut across study participants from a variety of biochemistry courses in the chemistry and biochemis

A critical review of the proposed definitions of fundamental chemical quantities and their impact on chemical communities (IUPAC Technical Report)

In the proposed new SI, the kilogram will be redefined in terms of the Planck constant and the mole will be redefined in terms of the Avogadro constant. These redefinitions will have some consequences for measurements in chemistry. The goal of the Mole Project (IUPAC Project Number 2013-048-1-100) was to compile published work related to the definition of the quantity \u2018amount of substance\u2019, its unit the \u2018mole\u2019, and the consequence of these definitions on the unit of the quantity mass, the kilogram. The published work has been reviewed critically with the aim of assembling all possible aspects in order to enable IUPAC to judge the adequateness of the existing definitions or new proposals. Compilation and critical review relies on the broadest spectrum of interested IUPAC members.Peer reviewed: YesNRC publication: Ye

Definition of the mole (IUPAC Recommendation 2017)

In 2011 the General Conference on Weights and Measures (CGPM) noted the intention of the International Committee for Weights and Measures (CIPM) to revise the entire International System of Units (SI) by linking all seven base units to seven fundamental physical constants. Of particular interest to chemists, new definitions for the kilogram and the mole have been proposed. A recent IUPAC Technical Report discussed these new definitions in relation to immediate consequences for the chemical community. This IUPAC Recommendation on the preferred definition of the mole follows from this Technical Report. It supports a definition of the mole based on a specified number of elementary entities, in contrast to the present 1971 definition.Peer reviewed: YesNRC publication: Ye

Best practices in the use of learning outcomes in chemistry education

Learning outcomes driven chemistry education is increasingly practiced, providing new opportunities for international comparisons. The interest in intended learning outcomes and constructive alignment has grown in many parts of the world due to both research in higher education (Biggs & Tang, 2011) and political decisions (e. g. the Bologna process in Europe). We will describe our steps towards a method for benchmarking (i.e. learning by sharing and comparing best practice) these outcomes, to enhance learner-centered chemistry education both in the developed and developing world. The project builds on and extends task group members’ experiences from national and international projects and draws on the international framework and multicultural competence of IUPAC’s Committee on Chemistry Education. Guiding chemistry education for the future requires the exchange of perspectives on core knowledge, skills and competencies. This project evaluates how learning outcomes for courses and modules are linked to each other and to learning outcomes for educational programs and how the expected learning outcomes can be aligned with learning activities and assessment. The comparison informs guidelines for self-evaluation, which focus on local learning outcomes for chemistry education including courses/modules, compared with national and/or international descriptors and with attention to alignment with learning activities and assessment. A full electronic report and manual for the benchmarking procedure will be produced at the conclusion of the project, including a collection of examples of good/best practice for dissemination. REFERENCES Biggs, J. B. & Tang, C. S. (2011). Teaching for quality learning at university: what the student does. Buckingham: Open University Press/Mc Graw-Hill Education

Assessment of course-based undergraduate research experiences: a meeting report

The Course-Based Undergraduate Research Experiences Network (CUREnet) was initiated in 2012 with funding from the National Science Foundation program for Research Coordination Networks in Undergraduate Biology Education. CUREnet aims to address topics, problems, and opportunities inherent to integrating research experiences into undergraduate courses. During CUREnet meetings and discussions, it became apparent that there is need for a clear definition of what constitutes a CURE and systematic exploration of what makes CUREs meaningful in terms of student learning. Thus, we assembled a small working group of people with expertise in CURE instruction and assessment to: 1) draft an operational definition of a CURE, with the aim of defining what makes a laboratory course or project a "research experience"; 2) summarize research on CUREs, as well as findings fromstudies of undergraduate research internships that would be useful for thinking about how students are influenced by participating in CUREs; and 3) identify areas of greatest need with respect to CURE assessment, and directions for future research on and evaluation of CUREs. This report summarizes the outcomes and recommendations of this meeting

The kinetics and energetics of tungsten hexacarbonyl and cyclopentadienyl manganese tricarbonyl, reactions with olefin molecules in the gas phase

The photochemistry of transition metal carbonyls is an actively studied field, in part, because of the wide variety of synthetic and catalytic precursors that can be generated during photolysis. Many catalytic processes are induced by these species including hydrogenation, hydrosilation, and isomerization of olefins. To understand these types of reactions we must know the energetics and dynamics of the bond making and bond breaking processes. Unfortunately, while significant information has been gained in the area of fundamental kinetic parameters, almost no progress has been made in the examination of the basic energetics of these complex processes. The kinetic study of reactions of isolated unsaturated molecules in the gas-phase offers the advantage of a perspective on energetics and dynamics that is free from solvent effects. In the gas-phase the interaction between a potential ligand and an isolated nonsolvated unsaturated species can be studied in detail. This thesis reports the investigation of the elementary kinetics and energy barriers for the unimolecular decay of W(CO)\sb5(olefin) and CpMn(CO)\sb2(olefin) systems. W(CO)\rm\sb5(C\sb3H\sb6) and W(CO)\rm\sb5(C\sb2H\sb4) are unstable in the gas phase and react with CO by dissociative substitution. Differences in reactions rates compared with Cr(CO)\sb6 are analyzed in terms of possible structural variations in critical configuration. Implications for trends in photocatalyzed reactions are considered. We also report the generation of gas phase CpMn(CO)\sb2(olefin) complexes for a series of increasingly branched olefin ligands. The stability of these complexes correlates strongly with steric hindrance. We find that infrared spectra of CPMn(CO)\rm\sb2(C\sb2H\sb4) and CPMn(CO)\rm\sb2(C\sb3H\sb6) complexes agree well with solution phase data

Students’ understanding of mathematical expressions in physical chemistry contexts: an analysis using Sherin’s symbolic forms

Undergraduate physical chemistry courses require students to be proficient in calculus in order to develop an understanding of thermodynamics concepts. Here we present the findings of a study that examines student understanding of mathematical expressions, including partial derivative expressions, in two undergraduate physical chemistry courses. Students participated in think-aloud interviews and responded to a set of questions involving mixed second partial derivatives with either abstract symbols or thermodynamic variables. The findings describe students' ability to transfer mathematics knowledge to chemistry problems and how students use symbolic forms described b