Final answer:
When the cobalt chloride strip is held just above the boiling water, it changes color from blue to pink, indicating the presence of water vapor in the air above the boiling water.
Step-by-step explanation:
When the cobalt chloride strip is held just above the boiling water, it changes color from blue to pink. This indicates that the molecules in the air above the boiling water contain water vapor. Cobalt chloride is a hygroscopic substance, meaning it can absorb and retain moisture from the environment. The change in color of the strip suggests that the air above the boiling water is saturated with water vapor.
Learn more about molecules in the air above boiling water