Understanding the physical and chemical changes on the three levels of the presentation of chemical concepts in students primary education

摘要

Physical and chemical changes are learning contents that address the essential chemical concepts in processes at particle level. When explaining chemical concepts at particle level, it is necessary to use various and appropriate visualization elements, such as (1) pictures, (2) photographs, (3) film excerpts (4) 2D or 3D stationary submicroscopic representations, (5) 2D and 3D dynamic contamination schemes, etc. This way, teachers can explain and interpret a chemical concept on three presentation levels: (1) macroscopic, (2) submicroscopic and (3) symbolic. The teacher’s task is to appropriately present the learning content, thus preventing understanding issues and numerous misconceptions. During this, the pupils create own mental models for each chemical concept, which develops during their interaction with the environment. Appropriately interpreted information of new chemical concepts is saved in the long-term memory without developed misconceptions only if the pupil simultaneously connects the information on three presentation levels. With an appropriately developed mental model, the pupils understand the chemical concept in its entirety, which ensures more durable and high-quality knowledge. This way, the pupils develop their scientific literacy and acquire appropriate knowledge, which can be used in further education to successfully upgrade individual scientific and chemical concepts. The purpose of this bachelor’s thesis is to establish the level of understanding of the selected chemical concepts on three presentation levels in relation to the following chemical learning contents: (1) states of matter, (2) transformation between states of matter, (3) pure substance, (4) element, (5) compound, (6) mixture and (7) chemical reaction. In addition, the purpose of this bachelor’s thesis was also to identify any misunderstandings of selected chemical concepts on a sample of 81 1st year BA students, Primary Education. The results show that for the selected chemical concepts, the students have developed misconceptions – 80.2% of students do not understand the condensation process and 64.2% percent of students do not recognize particles in element mixtures. Students have the most problems and misconceptions about the chemical reaction equation based on the submicroscopic presentation of particles. With appropriate teaching methods, it would be necessary to identify and eliminate misconceptions in future primary school teachers, so that they would be able to correctly present the selected chemical concepts to pupils.udud