Mental Models and Understanding Student of Grade XI High School in the Reaction Rate Material

Each individual uses mental models in an effort to solve a problem, so is the reaction rate in the learning process. The
purpose of this study was to obtain an overview of mental models and understanding of high school students (SMA) on the material
reaction rate. The method used is descriptive research method. Subjects consisted of 35 high school students in the city of Padang State
academic year 2018/2019. Instrument used is a two-tier diagnostic test and semi-structured interview guides. The results showed that
students' understanding at the submicroscopic level for the material reaction rate is low and the students have not been able to
interconnect all three levels of representation as well. Categories students' mental models ranging from the intermediate 2, intermediate
3 and the target model.