NAME: ______DATE: ______PERIOD: ____

CLOUD IN A JAR

Condensation is the process by which water vapor in the air is changed into liquid water. Condensation is crucial to the water cycle because it is responsible for the formation of clouds. These clouds may produceprecipitation, which is the primary route for water to return to the Earth's surface within the water cycle. Condensation is the opposite ofevaporation.

You don't have to look at something as far away as a cloud to notice condensation, though. Condensation is responsible for ground-level fog, for your glasses fogging up when you go from a cold room to the outdoors on a hot, humid day, for the water that drips off the outside of your glass of iced tea, and for the water on the inside of the windows in your home on a cold day.

The phase change that accompanies water as it moves between its vapor, liquid, and solid form is exhibited in the arrangement of water molecules. Water molecules in the vapor form are arranged more randomly than in liquid water. As condensation occurs and liquid water forms from the vapor, the water molecules become organized in a less random structure, which is less random than in vapor, and heat is released into the atmosphere as a result (USGS).

How do real clouds form?

Clouds require three things to form:

  • Water molecules
  • Cloud condensation nuclei - dust or air pollution
  • Temperature or pressure changes

Water molecules are in the air all around us, even though we can't normally see them. Normally, these water molecules bounce around.

Real clouds form when warm air rises in the atmosphere and cools down.Cloud condensation nuclei, such as small particles of dust and pollution, enable water molecules to stick together and stop bouncing around. The water molecules condense around the nuclei to form clouds. Clouds are just groups of tiny water droplets that stick together around cloud condensation nuclei when temperatures are low.

MS-ESS2-4 / Standard / Develop a model to describe the cycling of water through Earth’s systems driven by energy from the sun and the force of gravity.

HYPOTHESIS: The interaction of the warm water and the bag of ice will create water vapor.

RELEVANCE: Condensation has a direct connection to precipitation, which is the main mechanism that returns water to the Earth’s surface.

VARIABLES:

Independent variables – Water and the matches

Dependent variables – Cloud

Control- Glass jars

MATERIALS: boiling water, jar, matches, bag of ice

PROCEDURES:

  1. Pour boiling water into jar about ¾ of the way up.
  2. After 1 minute, pour ¾ of the water out of the jar.
  3. Light a match and hold it at the top of the jar for a few seconds.
  4. Drop the match inside AND put the bag of ice on top right away.
  5. Notice the interaction between the warm wet air and the cold air.

Directions: Construct a claim-evidence-reasoning regarding the effects of condensation in the hydrologic cycle as exhibited by the model of the cloud.

CLAIM (1 SENTENCE): ______

EVIDENCE (2+ SENTENCES DERIVED FROM DATA COLLECTION): ______

REASONING (3+ SENTENCES): ______