[1]
Purpose
[stextbox id = “info”] To assess growth in students’ understanding of the particle model of matter and how the model explains why the volume of the alcohol and water combined is less than their volumes individually.[/stextbox]
Description
[stextbox id = “info”] Revisit the super strong glasses scenario from Student Experience 3. Have students again draw what they would see in the graduated cylinder filled with water and alcohol using this task sheet [2]. [Task instructions for pilot teachers. [3]] [/stextbox]Questions to Ask Students
[stextbox id = “info”]- Describe your drawings. What does each part represent?
- How is your new drawing different from your first one? What have you learned that affected your new drawing?
- How does your drawing explain why the volume of the water and alcohol together was less than it was when they were separate?
- How does your drawing compare to the model using marbles and sand?
- [/stextbox]
Student Thinking
[stextbox id = “info”] Students’ drawings should show evidence of particle thinking by including how the water and alcohol particles mix together to fill empty spaces between the particles. If they do not, revisiting the marble and sand model might help.[/stextbox]
Implementation Tips
[stextbox id = “info”] Challenge students to add more detail than they included in their first drawing, even those students who included particles the first time.[/stextbox]