Water cycle

Overview

Students learn how the water cycle works using scientific enquiry: they will observe a model of evaporation and condensation, then record patterns and use evidence to answer questions. The lesson builds on KS2 pupils’ experience of observing changes and comparing results.

Learning intentions

• Students will describe the main stages of the water cycle: evaporation, condensation, precipitation, and collection.
• Students will explain how the Sun’s energy drives changes in water as it cycles.
• Students will plan and carry out a fair test using controlled variables to investigate evaporation.
• Students will use scientific evidence from a model and data to answer questions about water cycle processes.

Success criteria

• I can name the key stages of the water cycle in the correct order.
• I can explain what is happening to water during evaporation and condensation.
• I can collect simple measurements and compare results to justify my answer.
• I can identify a variable I kept the same for a fair test and explain why.

Curriculum links

• Scientific enquiry: choosing appropriate ways to answer questions, including comparative and fair tests.
• Analysing patterns more systematically by recording observations and measurements.
• Exploring and talking about ideas, asking questions, and using evidence to refine explanations.
• Noticing life-cycle and environmental changes through observing processes over time.

Key vocabulary (write and display)

• water cycle
• evaporation
• condensation
• precipitation
• collection
• water vapour
• Sun’s energy
• temperature
• variables
• fair test
• control
• measure
• evidence

Lesson structure (60 minutes)

1. 0–5 min · Hook with a question. Teacher shows a simple diagram of the water cycle (no labels revealed) and asks, “Where does the water in clouds come from?” Students turn-and-talk, then share one idea.

2. 5–12 min · Activate knowledge and introduce stages. Teacher records student ideas in two columns: “What I think” and “What we can test/observe,” then teaches the key stages using brief examples. Students write a 4-step “First/Next/Then/Finally” draft description of the cycle.

3. 12–22 min · Model exploration (evaporation & condensation). Teacher sets up a clear jar model: warm water in a tray/jar, with a clear cover/glass plate above to show water vapour condensing into droplets. Students observe for 6–8 minutes, drawing what they see and noting any changes in “time order” sentences.

4. 22–30 min · Whole-class reasoning: connect evidence to explanations. Teacher prompts: “What evidence shows condensation happened?” and “What might be causing evaporation?” Students answer using sentence starters: “I can tell because…” and “This suggests that…”

5. 30–43 min · Fair test investigation: evaporation rate. Teacher explains the task: investigate how evaporation changes with one variable. Example setup: three identical containers with equal water volume, same surface area; change only temperature (e.g., warm water bath, room temperature, cooler water bath). Students record initial measurements, start timing, and measure remaining water volume at set intervals (e.g., 5, 10, 15 minutes).

6. 43–52 min · Data, patterns, and comparison. Teacher models how to plot a simple bar chart or line graph from class data (or teacher-assisted readings). Students complete a short “Pattern” statement: “As temperature increases, evaporation seems to…” and discuss whether results support their idea.

7. 52–58 min · Water cycle application: extend to precipitation and collection. Teacher brings students back to the cycle diagram and asks them to match the model observations to “condensation” and “collection.” Students complete a quick sequence check: they order the stages and add one sentence for each stage using evidence (from their observations or test results).

8. 58–60 min · Exit ticket. Students answer two prompts:

• “Explain evaporation and condensation using the word ‘water vapour’.”
• “Which variable did you control in your fair test, and why?”

Resources

• Water cycle diagram (partly blank for the hook)
• Clear jar or container model, tray, clear lid/glass plate
• Warm water, measuring jug, thermometer (if available)
• Stopwatch/timers
• Measuring cylinders or beakers for volume
• Containers (one per group), labels, paper towels
• Data recording sheets and graph paper
• Sentence starter strips for explanations
• Whiteboard/marker/board pen

Assessment

• Formative: teacher listens to student explanations during turn-and-talk and model discussion (check for misconceptions such as “water disappears”).
• Formative: observe fair test planning and check students identify controlled variables.
• Exit ticket: assess accurate use of vocabulary and evidence-based reasoning (evaporation/condensation; controlled variable).

Differentiation

• Support: provide sentence starters (“Evaporation happens when…”, “Condensation is when…”) and a word bank with the water cycle stages.
• Support: offer a partially completed fair test table (variables, control, method) for pupils who need structure.
• Extension: ask advanced pupils to propose how precipitation could be modelled and what variable would affect it (e.g., cooling rate).
• EAL/SEN: allow oral rehearsal with a partner before writing; use picture cards for each stage (evaporation, condensation, precipitation, collection). Ensure key vocabulary is visually displayed throughout.

Key vocabulary (teacher prompts for use)

• “Use evidence: I can tell because…”
• “What did you keep the same? That’s your control.”
• “Which stage matches your observation?”