摘要：The purpose of this study was to examine students' achievements and cognitive loads at different levels of chemistry representations. The research was carried out among students majoring in chemistry teaching. A test was used as a measuring instrument for knowledge evaluation. Each task contained three subtasks, in macroscopic, sub-microscopic and symbolic domain. Each subtask in the test was followed by a seven point Likert scale (ranging from 'extremely easy' to 'extremely difficult') for the evaluation of cognitive load. A parallel analysis of the obtained results has shown that students' evaluations of cognitive load are in accordance with the accomplishments achieved on the test. Students have estimated that the greatest cognitive load corresponds to sub-microscopic level, which resulted in the lowest achievements. The results have also shown that there are no major differences in the average students' achievements in macroscopic and symbolic level, which are also in line with the evaluated cognitive load. Hence, it can be concluded that the students are able to review the cognitive processes and to evaluate the difficulty of the task.
