The Rooftop Garden Dome Journal

Four Days Above the City

Nia keeps a field journal while helping in a city rooftop garden. She wants to study what happens to water inside a clear dome placed over a shallow tray. The dome is sealed around its base. Each morning, Nia measures the water level in the tray and weighs the entire sealed setup: the dome, tray, water, and air inside. She does not open the dome between measurements.

Nia also records what she can see. At first, the inside of the dome is clear. Later, small droplets appear on its inside surface. The droplets sometimes become fewer while the water level in the tray rises. Nia uses a second, uncovered tray as a comparison. Both trays begin with the same amount of water, and she checks them at the same time each day.

Nia cannot see separate water particles in the tray, the air inside the dome, or the droplets. She makes a model with small dots to represent water particles. The dots are symbols, not drawings of the particles' actual size. Her model should account for the measurements and observations without adding or removing water particles from the sealed setup.