Precipitation can take many different forms, including as rain, snow and hail. You can demonstrate precipitation to students by making rain over the stove. Place a hand mirror in a freezer for 30 minutes. While the mirror is freezing, fill a pot with water and heat it until it boils. Steam will rise from the pot. Hold the handle of the mirror with an oven mitt. Hold the mirror over the steam. The oven mitt will prevent your hand from burning in the steam. The steam will cause precipitation to fall from the mirror. This experiment can also be used to teach kids that when a high pressure area, represented by the hold mirror, meets a low pressure area, represented by the hot steam, precipitation can develop.
Condensation occurs when water vapor combines and becomes heavier, resulting in precipitation. You can demonstrate condensation to your students easily with only a glass and ice water. Fill a tall glass with very cold ice water, and leave it on a counter top for at least 10 minutes. The outside of the glass will be covered with condensation in the form of moisture droplets. You can use this experiment to teach your students that the moisture and clouds in the sky are caused by water vapor condensing in the air.
Evaporation is a term used to describe water transforming into microscopic droplets, which rise up into the atmosphere. You can demonstrate evaporation to your students with a simple experiment. Fill a cup or glass with water, and mark the level of the water line with a marker. Place the cup of water outside. Check on the water level every day. Over time, the water will evaporate out of the cup, and the water level will go down. If the cup is placed outside on sunny days, it will evaporate more quickly. You can use this experiment to teach your students that all of the Earth's bodies of water, including oceans, rivers, seas, lakes and streams, eventually evaporate into the sky to be transformed back into precipitation, like rain, hail and snow.