• Journal of the Korean Chemical Society
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• v.61 no.6
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• pp.378-387
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• 2017

In this study, we analyzed the causes of decrease in the number of students taking Chemistry ? in the College Scholastics Ability Test (CSAT) by analyzing the adequacy of the Chemistry I question in the CSAT and the recognition survey of students and teachers about the Chemistry I choice. We analyzed some questions in Chemistry I of the CSAT from the year 2014 to 2016. The questions were analyzed to determine whether they were appropriate to the curriculum content, achievement standard, and achievement level. The target of the survey for perception was 452 senior high school students and 68 science teachers. The result of the study showed that the questions in Chemistry I are somewhat difficult compared to the depth and achievement level required by the curriculum, and it also requires mathematical thinking ability. Students recognized the mathematical thinking and complex mathematical skills are needed to solve problems in Chemistry I. Teachers also thought that the choice of Chemistry I is unfavorable in aspect of meeting the minimum academic ability standard, and accordingly, they did not actively recommend students to take Chemistry I. Moreover, most of the teachers recognized that it is necessary to improve the direction of writing questions for Chemistry I. Therefore, setting questions that can be solved using chemical knowledge, not mathematical ability need to be addressed.

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1465-1468
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• 2014

In this study, an intermediate temperature ionic conductor, $Ce_{0.95}Eu_{0.05}P_2O_7$, was prepared by solid state reaction. The variation of conductivities with the pressure $pH_2O$ or time were studied. The highest conductivity of $Ce_{0.95}Eu_{0.05}P_2O_7$ sample was observed in dry air atmosphere at $300^{\circ}C$ to be $1.1{\times}10^{-4}S{\cdot}cm^{-1}$ and in wet air atmosphere ($pH_2O=7.4{\times}10^3Pa$) at $100^{\circ}C$ to be $1.4{\times}10^{-3}S{\cdot}cm^{-1}$, respectively. The log ${\sigma}$ ~ log ($pO_2$) plot result indicated that $Ce_{0.95}Eu_{0.05}P_2O_7$ was almost a pure ionic conductor under high oxygen partial pressure and a mixed conductor of ion and electron under low oxygen partial pressure.

• Journal of the Korean Chemical Society
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• v.61 no.4
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• pp.204-210
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• 2017

In this study, we analyzed the descriptions of the electron movement model and the oxidation number change model presented in the 2009 revised curriculum and textbooks. We also investigated chemistry education major teachers' conceptions of limitations of each model. The electron movement model and oxidation number change model were presented in the curriculum and the textbooks. However, hybrid model was also presented which fail to grasp the limitation of each model. The hybrid model explains redox reactions of covalent bond compounds by electron movement model or even if it explains redox reactions by oxidation number change model, this explanations have the problem of confusing the virtual electron movement with the actual electron movement. A questionnaire and interviews were conducted to investigate chemistry education major teachers' perceptions of redox reactions. As results, many teachers did not recognize the limitations of each model and had difficulties to distinguish redox reactions from acid-base reactions because of the hybrid model.

• Journal of the Korean Chemical Society
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• v.59 no.6
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• pp.508-519
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• 2015

In this study, the pre-service chemistry teachers’ understanding of potential energy curve was investigated. The subjects were 24 junior students and 26 senior students studying chemistry education in a college of education. A concept questionnaire consisted of thought experiments with different initial conditions was developed to survey the pre-service teachers’ conceptions of potential energy curve. The survey results showed that the pre-service chemistry teachers had difficulties to accept the negative values for potential energy and total energy. And they knew the mechanical energy conservation but they could not apply it properly to the thought experiment situations given in the questionnaire. Also they had the knowledge about the direction of force exerted between the two balls, but many of them believed that the balls would stop moving at the bottom of potential energy curve well. In addition, it was discovered that few pre-service teachers could relate the thought experiments to the chemical bonding, the liquefaction of gas, and the molecular vibration.

• Journal of The Korean Association For Science Education
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• v.31 no.4
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• pp.621-640
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• 2011

The purposes of this study were to analyze the PCK of pre-service chemistry teachers and to know the changes of in PCK before and after the educational practice. For this study, four pre-service teachers majoring in chemistry education were selected as proteges and one professor of chemistry education department participated as a mentor. For the analysis of pre-service teachers' PCK, proteges' instructions, mentoring process, and semi-constructed interviews were collected. According to the results, most of the elements of the PCK were lack of proteges' instructions before the mentoring, because they didn't know the necessary practical knowledge for instructions. They also didn't know how they could apply their knowledge to the instructions. However, most of the pre-service teachers developed their PCK through the mentoring. This study shows that pre-service teacher's PCK could develop effectively by well-formed programs of mentoring before and after the educational practice in college education for pre-service teachers.

• Journal of the Korean Chemical Society
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• v.65 no.5
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• pp.358-369
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• 2021

In this study, the contents of the electron transfer model presented in the 4 chemistry I and the 4 chemistry II textbooks of 2009 revised curriculum and 9 chemistry I textbooks and 6 chemistry II textbooks of 2015 revised curriculum were analyzed in the viewpoint of model's Ignorance. In addition, 3 questions were developed to find out whether 24 pre-service teachers were perceived of the Ignorance of the electron transfer model. As a result, Most textbooks explain the redox reaction of covalent bond substances, which is an inconsistent context of the electron transfer model, with mixing oxidation number change and electron transfer or with electron transfer. In addition, the change to the development and use of the model emphasized in the 2015 revised curriculum was not clearly revealed in the curriculum comparison. Most pre-service teachers incompletely perceived or did not perceive Ignorance of the electron transfer model. Only 1 pre-service teacher perceived Ignorance of the model. In conclusion, the textbook description needs to be improved so that Ignorance of the model is revealed when the textbook describes the inconsistent situation of the electron transfer model. And through the education for pre-service teachers, it is necessary to provide an opportunity for pre-service teachers to perceive Ignorance of the electron transfer model.

• Journal of the Korean Chemical Society
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• v.48 no.5
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• pp.527-536
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• 2004

This study researched 122 high school students?and 97 chemistry majored teachers?perceptions on evaporation and boiling compared heating and no heating situations. From the results, it was found that the teachers?thoughts of evaporation and boiling depend on the situation were stable, but students?thoughts were depend on the situations. The high school students thought evaporation as boiling on the situation of heating and thought boiling as evaporation on the situation of no heating. These phenomena were related to the explanations of science textbooks. In many textbooks, evaporation concept was explained in the situation of no heating and boiling concept was explained in the situation of heating.

• Journal of the Korean Chemical Society
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• v.65 no.6
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• pp.441-454
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• 2021

In this study, pre-service science teachers' difficulties in teaching practice were investigated from the perspectives of pre-service teachers and cooperating teachers. Nine pre-service teachers who were attending a department of chemistry education at a college of education in Seoul and participated in teaching practice, and two of their cooperating teachers participated in the study. Teaching practice were observed, documentary data were collected, and interviews were conducted. The collected data were analyzed using analysis method of grounded theory. As results of the analysis, the pre-service teachers had difficulties in preparing and executing lessons which include experiments, because education related to experiments in middle and high schools was insufficient at the college of education and environments of cooperating school were unfamiliar to them. They had difficulties in encountering various responses from students in student-centered activities and tried to control students. Cooperating teachers did not provide specific assistance to ensure the autonomy of pre-service teachers, so that pre-service teachers suffered. Guiding science club activities was a meaningful experience to pre-service teachers, but it was a burden on both pre-service teachers and cooperating teachers. Educational implications of these findings were discussed.

• Journal of The Korean Association For Science Education
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• v.37 no.2
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• pp.347-358
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• 2017

The purpose of this study is to research on the professional development of pre-service chemistry teachers in terms of personal practical knowledge(PPK), and draw a discussion for pre-chemistry teacher education. A reflective discussion through a Community of Practice(CoP) activity has been conducted with 5 pre-service chemistry teachers studying in a college of education located in Seoul. The analysis of the results reveals that 'Subject-matter knowledge' is leaning toward massive chemical contents, 'Curriculum knowledge' is below the level of selecting, analyzing, and applying curriculum materials. 'Instruction knowledge', especially the knowledge of chemistry experiment and research, is not enough to lead secondary students' scientific experiment. 'Milieu of school knowledge' is stunted in growth for the reason of communication-deficiency between a college of education and a community, and among education- related groups. 'Self-knowledge' has been diminished not only because there is a bad influence from college classmates not wanting to be a teacher, but also a lack of communication in the chemistry-education department which can make pre-teachers' belief strong. In conclusion, it is especially needed for the chemistry-education department to strengthen pre-teachers' 'Self-knowledge' in order to develop PPK. This study suggests operating 'a professional community' that has a periodic meeting with pre-service teachers, teachers, professors, community people, education practitioners, and researchers. In addition, it would be effective for increasing pre-teachers' PPK to reconsider depth and direction of 'Subject-matter knowledge', to give an opportunity to examine curriculum materials critically and reorganize them, to improve the course of chemistry experimental subject to the way of improving pre-teachers' leadership in chemistry inquiry experiment, and to raise the quality of educational service activities.

• Journal of The Korean Association For Science Education
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• v.28 no.1
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• pp.15-23
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• 2008

This study analyzed the thinking types of pre-service chemical cell chemistry teachers according to grade and tried to find out how the education for pre-service teachers had influenced their thinking types. This study found that the pre-service education had failed to form scientific conceptions. Some pre-service teachers thought that college education couldn't help them understand the knowledge about chemical cell. In addition, they are lacking in scientific conception. Even some of them who thought college education was helpful had wrong conceptions. Most of the pre-service teachers' thoughts could not exceed the level of the high school chemistry textbooks. But, Juniors had more scientific conception than other grades through the group discussions about chemistry textbooks' contents in the course of "Theory of Science Teaching Materials". So, Pre-service education should include the pedagogical knowledge with content knowledge treated in secondary school science textbooks for educational effects.