The “Cloud in a Bottle” is a popular demonstration in physical and earth science classrooms that shows state changes of water. Squeezing and releasing a capped bottle, with a slight bit of water in the bottle, should produce condensation, or “fog.” Lighting a match and pulling some of the smoke into the bottle enhances the “fog” effect.
This was our first “lab report” of the year in 9th grade earth science, and I wanted to treat this exercise with a little more rigor than just “cool class demo with matches.” This lab and report aims to have students:
1) see how pressure differences affect water’s state change, and the role of condensation nuclei. These are key foundational concepts for severe weather curriculum.
2) formulate and test a hypothesis.
3) review and reflect more deeply on the key concepts (1) through writing and critical thinking.
4) learn the basic structure of a lab report with a simple and quick hands-on activity that produces reliable results.
This .zip file contains an instruction sheet for pairs or small groups, an individual student worksheet (with key), and lab report rubric I used. Both .pdf and editable .doc files are included.
Lab materials you will need include: clear 2L bottles with labels removed, water, and matches. The number of bottles depends on class size and desired group size, but each pair/group should have one. I generally gave an extra credit point or two to students who brought in clear 2L soda bottles.