2. Water to Vapor

Condensation inside the 2-bottle system

This set of investigations focuses on what happens to water when it evaporates.

When water evaporates from a paper towel, what happens to it? Does it go somewhere else, or is it destroyed, gone forever? A closed system of two connected bottles allows students to investigate this question. The system also highlights the cycling from liquid water to water vapor and back to liquid water again (condensation). After it has become obvious that every drop of water in the lower bottle has evaporated, the water reappears in a different part of the system.

At the same time students start tracking evaporation in the 2-bottle system, they uncover and keep track of changes in their mini-lakes.


The Child and the Scientist