Evaporation and condensation
Use evaporation, condensation, precipitation, collection, transpiration, water vapour, runoff and groundwater to describe water changing form and moving along different paths in the water cycle
What a learner can do afterwards
- Describe a common water-cycle path using evaporation, condensation, precipitation and collection in a sensible order
- Distinguish 'evaporation' from 'condensation' and explain where each occurs in the water cycle
- Use 'water vapour' and 'precipitation' correctly in descriptions of weather and the water cycle
1 · Read
Water moves between land, oceans and air in the water cycle. It can be liquid water, solid ice or an invisible gas called water vapour. Water follows different paths. This lesson shows one common path and some other ways it can move.
Evaporation changes liquid water into water vapour. Sunlight often helps by warming water, but direct sunshine is not required. Condensation changes water vapour into liquid drops. Cooling air can cause condensation near the ground or high in the sky. Dew is liquid drops on a surface.
Water vapour is invisible gas. A visible cloud contains tiny liquid drops, solid ice crystals or both. Rain, snow, sleet and hail falling from clouds are precipitation. Water can then collect in rivers, lakes or oceans. Collection stores water until it moves again.
Runoff is water flowing over the ground. Groundwater is water stored in spaces in rock below ground; it can move through connected spaces. Plants take up water through roots. They release water vapour through leaves, a process called transpiration.
Fog contains tiny liquid drops in air near the ground. It is not invisible water vapour. A dry spell in one town does not stop Earth's water cycle. Water can still evaporate there while condensation or precipitation happens elsewhere.
Evaporation makes vapour; condensation makes liquid drops. Precipitation falls from clouds. Water collects, flows underground or passes through plants.
All three readings written for this dataset.
More to read
Water can take different paths
Rain may collect in a lake, flow over ground or soak below the surface. Water taken up by roots can return to the air through leaves.
These paths belong to the same water cycle. A four-stage model helps us learn some common changes, but it does not show every route or how long water stays in each place.
Stores and movements
An ocean, lake or glacier can store water. Spaces in rock underground can store it too.
Water moves between stores. Runoff carries water over ground. Evaporation changes liquid water into gas in the air. A store may gain or lose water over time. Keeping water clean helps protect supplies, but it does not guarantee enough water in every place.
Clouds are not invisible gas
Water vapour is gas that you cannot see. Condensation changes vapour into liquid drops.
A visible cloud contains tiny drops, ice crystals or both. Fog contains tiny drops near the ground. Cloud and fog are not visible patches of water vapour. Naming the form helps you distinguish these examples.
2 · Watch
Take it off screen
Where it sits
Learn first
Nothing; this is a starting point.
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.