Students' mental models of diffusion in a gas phase solution were studied through the use of the Structure and Motion of Matter (SAMM) survey. This survey permits identification of categories of ways students think about the structure of the gaseous solute and solvent, the origin of motion of gas particles, and trajectories of solute particles in…

This study aimed to explore students' cognitive patterns based on their knowledge and levels. Participants were seventh graders from a junior high school in China. Three relatively distinct groups were specified by Cluster Analysis: high knowledge and low ability, low knowledge and low ability, and high knowledge and high ability. The group of low…