Exploring Earth’s Changes

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Year Level:

Year 4

Learning Area:

Science | Earth and Space Sciences

Australian Curriculum Links:

ACSSU075 – Earth’s surface changes over time as a result of natural processes and human activity.
ACSIS071 – With guidance, identify questions in familiar contexts that can be investigated scientifically and make predictions based on prior knowledge.

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Unit Title:

Weathering and Erosion Explorations

Lesson Title (Lesson 1 of 3):

Introduction to Weathering

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Duration:

30 minutes

Class Size:

27 students

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Lesson Overview:

In this engaging and visually rich introduction to the topic of weathering, Year 4 students will explore how natural processes contribute to the breakdown of rocks and landforms. Students will learn the differences between physical and chemical weathering, connect the processes to observable features in the Australian landscape, and begin to identify these processes in their local environment. The lesson includes active participation through group discussion, visual identification, and a tactile matching activity.

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Learning Intentions:

By the end of this lesson, students will be able to:

• Define “weathering” and explain why it is important.
• Identify two main types of weathering: physical and chemical.
• Observe and describe real-world examples of weathering in the local or Australian context.

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Success Criteria:

Students will:

• Describe how rocks can change over time due to weathering.
• Correctly classify examples of weathering as physical or chemical during the group activity.
• Use scientific vocabulary such as "break down," "change," "chemical reaction," and "erosion."

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Resources Required:

• Interactive whiteboard or display screen
• PowerPoint presentation with photos of Australian landmarks (e.g. Uluru, The Twelve Apostles, coastal cliffs)
• Real rocks or rock images showing signs of weathering
• Laminated Weathering Cards (images with short descriptions)
• Magnifying glasses (enough for student groups)
• Student mini whiteboards and markers
• "Weathering Detective" worksheet (1 per student; includes scenes to describe and classify)

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Prior Knowledge:

Students may have a loose concept of rocks or natural features changing over time but likely have not formally encountered the scientific processes involved. This lesson assumes foundational understanding of Earth materials (such as rocks and soil).

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Lesson Sequence

1. Engage (5 minutes)

Hook: The Mystery Rock Box

Teacher brings out a closed box containing a set of “rocks” (some smooth, some broken, and one sugar cube for dramatic effect). Without showing contents, the teacher asks:

"Have you ever seen a rock that was cracked or crumbled? What do you think happened to it?"

Students offer quick think-pair-share answers on their mini whiteboards. The teacher then reveals the box items one by one, explaining that rocks don’t stay the same forever — they change over time!

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2. Explore (10 minutes)

Interactive Presentation: What is Weathering?

Using a PowerPoint presentation, the teacher introduces:

• The definition of weathering: “The process that breaks down rocks into smaller pieces.”
• The two main types:
  • Physical (e.g. wind, rain, temperature change)
  • Chemical (e.g. chemical reactions, rust, acids)

Each type includes:

• Visual examples from Australian locations (e.g. crumbling sandstone cliffs in Sydney, rust-coloured rocks in the Northern Territory)
• A short clip (muted or verbal description) of time-lapse or artist’s impression of weathering

Asking for volunteers to relate the images to their own environment (e.g., “Who’s seen cracks in a footpath after rain?”) helps student connection.

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3. Explain (5 minutes)

Concept Sorting Activity
Students are divided into groups of 3 (9 groups in total). Each group receives a set of laminated cards containing:

• Picture of a weathered object/location (bridge rusted, cracked driveway, eroded rock arch)
• A simple description

In groups, they:

• Read and observe
• Decide: Physical or Chemical?
  Using provided Magnifying Glasses for extra excitement, they classify the cards into types and hold up the answers using mini whiteboards.

Teacher circulates to ask open-ended questions like:

• “Why did you choose chemical for this one?”
• “Can we have more than one process acting at once?”

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4. Elaborate (5 minutes)

Weathering Detective Worksheet
Individually, students receive the Weathering Detective worksheet that includes:

• A landscape scene such as a coastal cliff
• Arrows pointing to features (crack in rock, discoloured stone)
• Short prompts:

a) What do you observe here?
b) Is it physical or chemical weathering? Why?

This task reinforces terminology and allows the teacher to assess comprehension.

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5. Evaluate (5 minutes)

Thumbs Up / Down Quiz Teacher conducts a quick yes/no-style formative quiz:

• “Does weathering happen quickly?” (No)
• “Is rust on metal from physical weathering?” (No)
• “Can plants help break rocks apart?” (Yes)

Finish the lesson by displaying a photo of a rusted car overgrown with vines in the Aussie outback. Ask:

“What do you think is happening to this car? Could rocks change in a similar way?”

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Differentiation:

• EAL and lower-literacy support: Visual-heavy presentation, paired discussion, clearly labelled diagrams
• Extension for fast finishers: Tasked with sketching their own outdoor scene showing both types of weathering
• Multi-modal engagement: Visual, verbal, kinaesthetic elements incorporated

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Assessment:

• Observation during classifying activity
• Verbal responses in group discussions
• Completed Weathering Detective worksheet (collected or self-assessed next session)

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Teacher Reflection (Post-lesson Prompt for Planning):

• Did students distinguish between physical and chemical weathering confidently?
• Were the local and national examples engaging and relatable?
• How can we build on curiosity for outdoor/environment learning next session?

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Next Lesson Preview:

Lesson 2: Physical Weathering in Action
We’ll get our hands dirty with experiments simulating how freezing water and plant roots can break rocks apart. Students become real-world geoscientists on the school grounds!

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This lesson is designed to spark curiosity and demonstrate the real impact of natural processes on the Aussie environment — making science both personal and powerful.