Download the printable Experiment Sheet here.
Precipitation occurs when water condenses in the atmosphere and forms droplets (or ice crystals, if the air is below freezing), and falls to the Earth. Precipitation occurs as rain (liquid water), sleet (frozen rain which freezes prior to the ground), snow (ice crystals at point of condensation), or hail (balls of ice formed during updrafts in large thunderstorms). Other variations of these have various names; drizzle, graupel, ice pellets etc. but all refer to water falling post-condensation from the sky in some form. In this experiment we simulate the condensation of warm water on a layer of cold air (plastic!) and it's dripping back down onto the Earth's surface.
Dry Ice or Water ice
Small Model Structure (optional)
- Add the optional house model to the bottom of the bowl and pour in the hot water.
- Cover the top of the bowl tightly with the plastic wrap.
- Carefully add dry ice to the top of the plastic wrap.
- Observe the underside of the plastic wrap over the next few minutes as water droplets form and begin to fall from the point under the ice on the plastic wrap back down to the "model" below.
Questions to consider:
- How did the heat of the water and cold of the dry ice react to each other?
- What do we call the process by which this new liquid water forms on the plastic wrap?
- What does the plastic wrap represent in nature?
- What types of precipitation have you personally observed?