Evaporation condensation and freezing of water for Primary 4

Class: Primary 4
Term: First Term
Week: 9
Age: 9 years
Duration: 45 minutes
Subject: Basic Science and Technology
Curriculum Theme: Our Environment
Focal competence: Applying scientific methods to interpret environmental processes involving water
Key competencies/values: Research and Problem Solving; Communication; Environmental Literacy; Creativity and Innovation
Skills:

• Identifying pure water with no colour, taste and odour
• Constructing models
• Carrying out simple experiments to determine changes when water is heated

Previous Lesson: Meaning properties and states of water
Topic: Water: Changes Of State
Subject Matter: Evaporation, condensation and freezing, simple heating/cooling observations

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain

• Explain evaporation, condensation, and freezing.

Psychomotor Domain

• Conduct a simple experiment to determine changes that take place when water is heated.

Affective Domain

• Appreciate the importance of observing changes of state in everyday life.

Reference Materials

The following resources were used in planning this lesson:

• 2025 Revised 9 Years Basic Education Curriculum
• Relevant State Unified Scheme of Work
• Basic Science and Technology for Primary 4
• The HeadTeacher Scheme of work

Instructional Materials

The teacher will teach this lesson with the aid of:

• Water
• Stove
• Metal cup or tin
• Ice/freezer
• Cardboard paper

Rationale for the Lesson

This lesson helps pupils understand how water changes its state due to heating and cooling. It provides a foundational understanding of natural phenomena like rainfall and the water cycle, connecting scientific concepts to their everyday observations. This knowledge also encourages scientific inquiry and observation skills.

Prerequisite/Previous Knowledge

Pupils should have basic knowledge of water, its uses, and that it can be found in different forms.

Lesson Content/Board Summary

Water: Changes Of State

Water can exist in three main states: solid, liquid, and gas. These states can change depending on whether water is heated or cooled.

Evaporation

Evaporation is the process where liquid water turns into a gas (water vapour) when heated. This often happens slowly, like when wet clothes dry in the sun, or quickly, like when water boils.

Examples of Evaporation:

1. Water drying from wet clothes.
2. Puddles disappearing after rainfall.
3. Steam rising from boiling water.

Condensation

Condensation is the process where water vapour (gas) turns back into liquid water when it cools down. This is the opposite of evaporation.

Examples of Condensation:

1. Dew drops forming on grass in the morning.
2. Fog or mist forming in the air.
3. Water droplets forming on the outside of a cold glass.
4. Clouds forming in the sky.

Freezing

Freezing is the process where liquid water turns into solid ice when it is cooled to a very low temperature (0°C or 32°F). The solid form of water is called ice.

Examples of Freezing:

1. Water turning into ice cubes in a freezer.
2. Ponds or lakes freezing over in very cold weather.

Simple Heating and Cooling Observations

When water is:

1. Heated: It changes from liquid to gas (evaporation). If heated enough, it boils.
2. Cooled: Water vapour changes from gas to liquid (condensation). Liquid water changes from liquid to solid (freezing) if cooled further.

Teaching Methods/Instructional Techniques

Discussion, Demonstration, Guided Practice, Question and Answer, Explanation, Observation, Practical Activity

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Questioning/Activating prior knowledge

Teacher’s Activity: The teacher greets the pupils and asks them to mention things they know about water, including where they find it and how it can look (e.g., cold, hot, ice). The teacher then introduces the topic: “Water: Changes of State.”

Pupils’ Activity: Pupils respond to the teacher’s questions and listen attentively to the introduction.

Learning Point: Water’s states of matter

Step 2: Explanation of Evaporation

Time: 7 minutes

Teaching Skill: Explanation/Demonstration

Teacher’s Activity: The teacher explains what evaporation is, using simple language and relatable examples like wet clothes drying. The teacher then places a small amount of water in a metal cup on the stove and begins to heat it, drawing pupils’ attention to any steam forming.

Pupils’ Activity: Pupils listen to the explanation and observe the water being heated on the stove.

Learning Point: Meaning of evaporation

Step 3: Observation of Evaporation

Time: 5 minutes

Teaching Skill: Observation/Questioning

Teacher’s Activity: As the water heats up and steam becomes visible, the teacher asks pupils what they observe happening to the water. The teacher guides them to understand that the liquid water is turning into an invisible gas (water vapour) and rising.

Pupils’ Activity: Pupils describe what they see happening to the water and identify the process as evaporation.

Learning Point: Observation of evaporation

Step 4: Explanation of Condensation

Time: 7 minutes

Teaching Skill: Explanation/Demonstration

Teacher’s Activity: The teacher explains condensation as the opposite of evaporation, where water vapour cools down and turns back into liquid water. The teacher holds a cold metal plate (or the cardboard paper if it’s cold enough from the freezer) above the steam rising from the heated water.

Pupils’ Activity: Pupils listen to the explanation and watch as the teacher demonstrates condensation.

Learning Point: Meaning of condensation

Step 5: Observation of Condensation

Time: 5 minutes

Teaching Skill: Observation/Guided discussion

Teacher’s Activity: The teacher directs pupils’ attention to the droplets of water forming on the cold surface. The teacher explains that this is water vapour cooling and changing back into liquid water.

Pupils’ Activity: Pupils observe the water droplets forming and understand the process of condensation.

Learning Point: Observation of condensation

Step 6: Explanation and Demonstration of Freezing

Time: 5 minutes

Teaching Skill: Explanation/Demonstration

Teacher’s Activity: The teacher explains that when liquid water gets very cold, it turns into solid ice. The teacher shows pupils a piece of ice (possibly from the freezer) and asks them to describe its properties (hard, cold, solid). The teacher explains that this is the freezing process.

Pupils’ Activity: Pupils observe the ice and describe its characteristics, understanding that it is frozen water.

Learning Point: Meaning of freezing

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. What happens to water when it is heated and turns into gas?
2. What is the process called when water vapour turns back into liquid?
3. What happens to liquid water when it gets very cold and turns solid?
4. Give one example of evaporation and one example of condensation.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Understanding changes of state

Step 8: Note-Taking

Time: 4 minutes

Teaching Skill: Guided Writing

Teacher’s Activity: The teacher guides pupils to copy the essential Board Summary notes on evaporation, condensation, and freezing into their notebooks.

Pupils’ Activity: Pupils copy the notes carefully into their notebooks.

Learning Point: Recording lesson notes

Step 9: Conclusion

Time: 2 minutes

Teaching Skill: Reinforcement

Teacher’s Activity: The teacher summarises the lesson by reminding pupils that water can change its state from liquid to gas (evaporation), gas to liquid (condensation), and liquid to solid (freezing) depending on temperature changes. The teacher praises pupils for their participation.

Pupils’ Activity: Pupils listen to the summary and ask any final questions.

Learning Point: Recap of water changes

Continuous Assessment/Further Study

Type: Homework

Instruction: Answer the following questions in your notebook:

1. Explain in your own words what evaporation means.
2. Give two examples of condensation you see at home.
3. What is the solid form of water called?
4. Draw a simple diagram showing water turning into ice.

Lesson Keywords

• Evaporation – The process of liquid turning into gas.
• Condensation – The process of gas turning into liquid.
• Freezing – The process of liquid turning into solid.
• Water vapour – Water in its gaseous state.
• Ice – Water in its solid state.

Differentiation

For weaker learners, the teacher will provide more direct guidance during the demonstration, repeating explanations and using simpler terms. They will be given pre-drawn diagrams of the processes to label. For faster learners, the teacher will encourage them to think about where else they might observe these changes of state in nature (e.g., clouds, fog) and challenge them to draw a simple water cycle diagram.

Suggested Lesson Videos

For further understanding, pupils can search on YouTube for: changes of state of water primary 4

Teacher Guide for Using This Lesson Plan

Before the lesson, ensure all instructional materials, especially the stove, metal cup, and water, are ready and in a safe working condition. Prepare ice ahead of time if a freezer is not readily available in the classroom. Begin by engaging pupils with questions about water to activate their prior knowledge. During the demonstration, clearly explain each process (evaporation, condensation, freezing) as it happens, allowing pupils to observe closely. Emphasise safety when handling hot water and the stove. Guide pupils to record their observations and the key definitions in their notebooks during the note-taking stage. Check for understanding by asking questions throughout the lesson and during the evaluation stage. Provide extra support to pupils who struggle to grasp the concepts and encourage faster learners to think about real-world applications of these changes of state.