We decided we had a good understanding of what we thought was happening with the closed cup systems, but we still had questions about what was really going on with the walls and the lid. We felt that zooming in on them would give us insight into how the mass of the cups does or doesn't change depending on whether there is a lid or no lid, and how this enables condensation to happen or not.
We went the 3D route using magnetic marbles to represent the walls and lids of the cup (solids are made of molecules, too). And we used glass marbles to represent the water in the cup (which we know can evaporate and possible leave the cup system if given the opportunity)!
We went the 3D route using magnetic marbles to represent the walls and lids of the cup (solids are made of molecules, too). And we used glass marbles to represent the water in the cup (which we know can evaporate and possible leave the cup system if given the opportunity)!
| We noticed a bunch of things from this... 1. The water that attempts to leave the cup system by evaporating can't leave. This means that it is trapped, and the mass of the cup can't change. 2. If any mass change occurs, it must have come from outside the cup! 3. The walls/lid of the cup seem to move a little when the water that's attempting to leave the cup system hit it. Interesting! |
We also felt that our marble model in 3D was missing the air molecules that are an important part of this system. So we went back to the 2D route and developed a model showing what is going on in many parts of both a closed and open cup system.
From here, we did a table-summary activity to determine what all these things have helped us figure out from zooming-in on a closed cup system! Way to go 6th graders!
Next steps: We must figure out how the temperature of a closed cup system does in fact change when the mass doesn't! Hmmm...