Look for evidence in the notebook entries. What happens when salt dissolves in water? Without accurate data, students will be unable to support claims that dissolved salt is present in the water even though it’s invisible.
Use these criteria to interpret students’ work:
Once students have collected and recorded accurate data, the next step is to ask them to make claims about whether dissolved salt still exists in the water even though you can no longer see it, and to use the weight and volume data they just collected to support their claims.