Evaporation & the Water Cycle
Identify the role of evaporation and condensation in the water cycle, and associate the rate of evaporation with temperature
What a learner can do afterwards
- Describe evaporation as liquid turning to gas and condensation as gas turning to liquid
- Explain the water cycle: evaporation from seas/lakes → condensation into clouds → precipitation
- Explain why warmer water evaporates faster when other conditions stay the same, such as equal puddles drying at different temperatures
1 · Read
You have learned change-of-state words. Evaporation changes liquid water at its surface into an invisible gas called water vapor. It happens without boiling, even on cool days. Condensation changes water vapor back into liquid water.
The Sun supplies energy for water to evaporate from seas, lakes and other wet places. Some vapor travels upward with air. As the air cools, vapor can condense into tiny liquid cloud droplets. Clouds can also contain ice. Water falls as precipitation, such as rain or snow. It collects on Earth and can evaporate again. The cycle has no fixed beginning.
After a shower, invisible water vapor is in the bathroom air. At a cool mirror, some vapor condenses into liquid drops. These make the mirror look misty. Visible mist in the air is also tiny liquid drops, not the invisible gas. Keep away from hot water and ask an adult before a test.
Water is made of tiny moving particles. Warming makes them move faster and gives them more energy to escape from the surface. This speeds evaporation. Wind and how damp the air is also affect drying. To compare temperature alone, keep those conditions, the water amount and the exposed area the same. After the same time, less water left means more has evaporated.
Evaporation makes vapor; condensation makes liquid drops. Water cycles through Earth and air. Warmer water evaporates faster when other conditions stay the same.
The lesson, questions and study cards were written for this dataset. Numerical evaporation results are illustrative examples, not published measurements.
These two readings and five study cards were written for this dataset.
More to read
A path through the water cycle
Begin with water in a lake. Some leaves its surface as invisible water vapor. Moving air can carry that vapor elsewhere. If the air cools enough, some vapor condenses into liquid cloud droplets.
Water can fall from clouds as rain or snow. Rain may flow into streams or soak into the ground. Some water later reaches a lake or the sea and can evaporate again. This is one path through the cycle, not a fixed starting point. Water can spend different lengths of time in different places.
Where outside drops come from
A closed cold-water bottle can become wet on the outside. Water vapor from the surrounding air can condense into liquid drops at its cold surface. The water does not need to leak through the bottle.
Dew can form in a similar way. Grass or leaves cool enough for water vapor to condense into drops on their surfaces. The gas changes to liquid. Invisible vapor and visible drops are the same substance in different states.
2 · Watch
En anglaisTake it off screen
Where it sits
Optional connections
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.