• Journal of the Korean Chemical Society
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• v.64 no.1
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• pp.30-37
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• 2020

The purpose of this study was to identify the problems faced by students in sub-microscopic representation of acid-base reactions. Herein, we selected 30 students of 12^th grade science classes, who had studied various acid-base models. In order to investigate the sub-microscopic representation ability of the students, we developed nine items related to various contexts, such as one type of solute and solvent, two types of solutes and solvent, cases with water as solvent or with nonaqueous solvents. For all items, we consistently observed lack of concept of chemical change. In context of aqueous and nonaqueous solutions, the frequency of lack of concept of chemical bonding was high if ammonia was the solute or solvent. Moreover, the frequency of lack of concept related to the degree of electrolytic dissociation was high. Therefore, chemistry teachers should understand that students' ability to sub-microscopic representation of acid-base reactions can be enhanced by analyzing the difficulties faced by the students in solving diverse acid-base problems.

• Journal of The Korean Association For Science Education
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• v.32 no.8
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• pp.1333-1344
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• 2012

This study aimed to enhance creative problem solving skill by using the Creative Problem Solving (CPS) learning model which was developed based on creative problem solving approach and five essential features of inquiry. The key strategy of the CPS learning model is using real life problem situations to provide students opportunities to practice creative problem solving skill through 5 learning steps: engaging, problem exploring, solutions creating, plan executing, and concepts examining. The science content used for examining the CPS learning model was "matter and properties of matter" that consists of 3 learning units: Matter, Solution, and Acid-Base Solution. The process to assess the effectiveness of the learning model used the experimental design of the Pretest-Posttest Control-Group Design. Seventh grade-students in the experimental group learned by the CPS learning model. At the same time, students at the same grade level in the control group learned by conventional learning model. The learning models and students' prior knowledge levels were served as the independent variables. The creative problem solving skill was classified in to 4 aspects in: fluency, flexibility, originality, and reasoning. The results indicated that in all aspects, the students' mean scores of creative problem solving between students in experimental group and control group were significantly different at the .05 level. Also, the progression of students' creative problem solving skills was found highly progressed at the later instructional periods. When comparing the creative problem solving scores between groups of students with different levels of prior knowledge, the differences of their creative problem solving scores were founded at .05 level. The findings of this study confirmed that the CPS learning model is effective in enhancing the students' creative problem solving skill.

• Journal of Korean Elementary Science Education
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• v.36 no.4
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• pp.346-355
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• 2017

The 2015 revised national science curriculum encourages students to cultivate the science core competencies such as scientific thinking, science process skills, scientific problem-solving ability, scientific communication skill, scientific participation and lifelong learning ability. To fill this purpose, we practiced science writing classes based on core competencies and examined the effect of its application. The target unit was 'weather and our life', 'acid and base', 'speed of an object', and 'structure and function of our body' in the fifth grade of elementary school. The results were as follows. First, it was proven that science writing activities based on core competencies did not help improving science process skills of learners. Second, it had a significant effect on the improvement of the learner's self-directed learning ability, in particular, owner spirit, meta cognition and information search. Third, this strategy for science writing changed learners' scientific attitude positively. The above-mentioned results show that this science writing classes can be applicable as one of effective methods in cultivating science core competencies.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.651-660
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• 2007

Acid drainage has been recognized as an environmental concern in abandoned mine sites for long time. Recently, the environmental and structural damage by acid drainage is a current issue in construction sites in Korea. Here, the author introduces the type of damages by acid drainage in construction sites and emphasizes the importance of geoscience discipline in solving the problem. Metasedimentary rock of Okcheon group, coal bed of Pyeongan group, Mesozoic volcanic rock. and Tertiary sedimentary and volcanic rocks are the major rock types with a high potential for acid drainage upon excavation in Korea. The acid drainage causes the acidification and heavy metal contamination of soil, surface water and groundwater, the reduction of slope stability, the corrosion of slope structure, the damage on plant growth, the damage on landscape and the deterioration of concrete and asphalt pavement. The countermeasure for acid drainage is the treatment of acid drainage and the prevention of acid drainage. The treatment of acid drainage can be classified into active and passive treatments depending on the degree of natural process in the treatment. Removal of oxidants, reduction of oxidant generation and encapsulation of sulfide are employed for the prevention of acid drainage generation.

• Journal of the Korean Chemical Society
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• v.63 no.6
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• pp.486-504
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• 2019

This study analyzed achievement standards in the 2015 Science Education Standards as well as activities and assessment items in the Integrated Science, Chemistry I, and Chemistry II textbooks using science core competencies and subcomponents. All five scientific core competencies, in order of scientific thinking capacity, scientific inquiry capacity, scientific communication capacity, scientific problem solving capacity, and scientific participation and lifelong learning capacity, were included in the achievement standards of Integrated Science. Scientific thinking capacity, scientific inquiry capacity, and scientific communication capacity were included in the achievement standards of Chemistry I. The achievement standards of Chemistry II only included scientific thinking capacity. All five scientific core competencies were involved in activities of Integrated Science, Chemistry I, and Chemistry II textbooks and the highest propotion was scientific thinking capacity and scientific inquiry capacity. All five scientific core competencies were involved in assessment items of Integrated Science, Chemistry I, and Chemistry II textbooks and the highest proportion was scientific thinking capacity.