Water States Exploration

WALT (We Are Learning To)

• Understand the three states of water: solid, liquid, and gas.
• Identify and observe the melting, freezing, and boiling points of water.
• Explore evaporation and changes in state over time.

Curriculum for Excellence Links

• SCI 2-14a: I can demonstrate my understanding of changes in states of matter, such as melting, freezing, and evaporation, and relate these to everyday experiences.
• SCN 2-05a: I can describe the properties of everyday materials and explore how they can be changed by heating and cooling.
• Experiences and Outcomes Level 2: Recognise and investigate changes in materials.

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Success Criteria

• I can name and describe the three states of water.
• I can explain what happens at 0°C (freezing/melting point) and 100°C (boiling point).
• I can observe and record changes in water state using ice, liquid water, and steam (through discussion).
• I can explain evaporation as water changing from liquid to gas.

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Resources

• Ice cubes (enough for 28 students or 14 pairs)
• Transparent plastic cups or beakers with fill lines marked
• Warm safe water (pre-prepared in cups)
• Timer or clock with second hand
• Whiteboards and markers or science notebooks
• Large laminated chart showing water states and temperature points (0°C and 100°C)
• Dyslexia-friendly printed sheet with simple, clear text and illustrative pictures on water states

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Lesson Structure (45 mins)

1. Introduction (10 minutes)

• Interactive Discussion: Start by asking pupils what they know about water. Can they name different forms it can take?
• Introduce the words solid, liquid, gas. Use simple definitions and examples.
• Show the chart with water states and temperature points (0°C freezing/melting; 100°C boiling).
• Explain these points in context: e.g., “Ice melts at zero degrees” and “Water boils at one hundred degrees”.

Differentiation: Use the dyslexia-friendly sheet here. Allow pupils who need more time to read and absorb this quietly or with a partner.

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2. Practical Investigation Part 1 – Melting (10 minutes)

• Hand out an ice cube to pairs of pupils. Ask them to observe and discuss: What is happening to the ice?
• Let them hold the ice and watch it melt at room temperature. Guide them to notice the temperature it happens at (~0°C inside freezer, warms at room temp).
• Ask pupils to write or draw what they see in whiteboards or notebooks.

Extension: Advanced learners record estimated time for ice to fully melt and hypothesise what may speed up or slow down melting.

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3. Practical Investigation Part 2 – Evaporation (10 minutes)

• Give each pair a transparent plastic cup with warm water marked to a specific fill line.
• Ask them to predict what will happen if the water is left out during the day. Will the water level change? Why?
• Explain evaporation as water turning into gas slowly over time.
• Pose the challenge: “How will you be sure the water is evaporating?” Use the marked fill lines as observational evidence.
• For this lesson, pupils can observe and note changes over short term (some pupils may see slight changes), but explain it is a slower process.

Differentiation: Support with sentence starters for recording, e.g., “The water level is... because...”

Extension: Encourage advanced learners to explain how temperature affects evaporation rates, relating back to the boiling point.

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4. Teacher Demonstration – Boiling Point (5 minutes)

• Due to safety, teacher demonstrates boiling water or shows a video of water boiling at 100°C.
• Discuss what is happening: water changes from liquid to gas quickly, this is called boiling.
• Relate this to evaporation, but faster due to heat.

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5. Conclusion and Review (10 minutes)

• Recap all states of water and key points about melting, freezing, boiling, and evaporation.
• Ask pupils to work in pairs to label pictures of water in ice, liquid, and steam states.
• Use a quick quiz or “show me” method with whiteboards:
  • What state is ice? (solid)
  • What temperature does ice melt? (0°C)
  • What state is water in the cup? (liquid)
  • What happens if water gets very hot? (boils, turns to gas)
  • What is evaporation? (water changing from liquid to gas slowly)

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Assessment / Observations

• Observe participation and verbal responses during discussion and practicals.
• Check notebook/whiteboard drawings and sentences for understanding.
• Use questioning during recap to assess comprehension.

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Differentiation Strategies

• Use pair work to support less confident learners.
• Use clear, dyslexia-friendly resources with visuals and simple language.
• Provide sentence starters for written work.
• Scaffold explanations with concrete examples and hands-on materials.

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Extension Activities

• Investigate what happens to water levels in different temperatures or environments (e.g., outside, near heater).
• Encourage pupils to research or bring in examples of evaporation in nature (puddles drying, laundry).
• Explore freezing/melting times for different-sized ice cubes.

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By closely aligning to Curriculum for Excellence outcomes, this lesson encourages active, hands-on learning and supports diverse learner needs while fostering curiosity about everyday scientific phenomena!