Water cycle diagram

What this diagram shows

Earth's water is not used up. It moves around and around in a cycle powered by the Sun's heat and by gravity. This diagram shows four stages. In Explore, tapping a stage gives its name and a short explanation. Labels names every stage on the picture. Quiz me asks the child to find each stage and gives a score at the end of the round.

• Evaporation: the Sun warms water in seas, lakes and puddles, and some turns into invisible water vapor that rises.
• Condensation: as the vapor rises it cools and turns back into tiny droplets of liquid water, forming clouds.
• Precipitation: droplets join together and fall as rain, snow, sleet or hail once they are too heavy to stay up.
• Collection: water gathers in oceans, lakes, rivers and underground, ready to evaporate again.

Common misconceptions

Many children think clouds are made of water vapor, or of smoke or cotton. Water vapor is an invisible gas. Clouds are made of tiny drops of liquid water, or ice crystals, small enough to float. The same is true of the "steam" you see above a kettle: the visible part is droplets that have already condensed.

Other mix-ups: thinking water only evaporates when it boils (puddles evaporate at everyday temperatures), that rain comes from a cloud that is "full" like a bucket, or that the cycle always goes neatly ocean to cloud to rain. Real water can sit in a glacier or underground for thousands of years. Plants also release water vapor from their leaves, called transpiration, which this diagram does not show as a separate stage.

Where this fits in school

• England, Year 4: in the states of matter unit, pupils identify the part played by evaporation and condensation in the water cycle and link the rate of evaporation to temperature.
• England, Key Stage 2 geography: pupils describe key aspects of physical geography, including the water cycle.
• US, grade 2: NGSS 2-ESS2-3 asks students to show where water is found on Earth and that it can be solid or liquid.
• US, grades 6 to 8: NGSS MS-ESS2-4 asks students to model the cycling of water through Earth's systems, driven by energy from the Sun and the force of gravity.

A 10-minute water cycle activity

• Ask: "Where does rain come from?" and "Where does a puddle go when it dries up?" Note the answers.
• In Explore, tap evaporation, condensation, precipitation and collection in order.
• Ask which stage needs the Sun's energy (evaporation) and which needs gravity (precipitation).
• Return to the opening questions and see if the answers have changed.
• Play a Quiz me round, then have the child draw the cycle with arrows from memory.

A quick home demonstration: put warm water in a clear bowl, cover it with plastic wrap, and place a few ice cubes on top. Within minutes, droplets form under the cold wrap and drip back down, showing evaporation, condensation and precipitation in one bowl. Use warm tap water, not boiling water.

Learning more

Science is part of Eurekami's skill map, with lessons that draw science diagrams live and narrate them in English or Spanish. Daily Practice brings a skill back for review when it starts to fade.