[1]
Purpose
To assess growth in students’ understanding of the particle model of matter and how the model explains what happens to liquid water during evaporation.
Description
Revisit the super strong glasses [2] scenario from Student Experience 1. Have students again imagine that they are wearing super strong glasses [2] and draw a picture that illustrates what they saw happening to the water in the dog’s water bowl using this task sheet [3]. [Task instructions for pilot teachers. [4]]
Questions to Ask Students
- Describe what’s in your drawing. What does each part represent?
- How is this drawing different from your first one?
- How could you use what you just drew to explain how the puddle on the pan (from Student Experience 4) disappeared?
Student Thinking
Some students may still believe that matter (in this case water) is continuous rather than made up of particles (in this case water molecules) (Benson et al., 1993; Nakhleh & Samarapungavan, 1999; Renström et al., 1990; Séré, 1986) [5]. These students are likely not to include water particles, or any other kind of particles, in their drawings.
Implementation Tips
- Challenge students to add more detail than they included in their first drawing, even those students who included particles the first time.
- The simulation will not convince all students that matter is made of particles and that those particles leave the liquid and enter the vapor phase. Look carefully at students’ new drawings to see if they have kept some of their earlier ideas.