Science · Year 1 · Material World: Properties and Purpose · Term 1

Material Properties: Absorbency and Waterproofing

Students will test materials to determine if they are absorbent or waterproof, understanding the practical applications of these properties.

• ACARA Content Descriptions
• AC9S1U03
• AC9S1I03

About This Topic

Combining and Changing Materials explores how we can alter the properties of substances by mixing them, heating them, or cooling them. Under AC9S1U03, students investigate how materials can be physically changed (like scrunching paper) or combined to create something with new properties (like mixing flour and water). This topic introduces the idea that the world is dynamic and that humans can manipulate materials to suit their needs.

This topic provides a bridge to understanding food science and traditional practices. For example, students can learn about how First Nations people processed toxic seeds to make them safe to eat through soaking and grinding. This topic is best taught through hands-on 'kitchen science' where students can see immediate transformations and discuss whether those changes can be reversed.

Key Questions

1. Analyze why a towel is absorbent and a raincoat is waterproof.
2. Design a test to compare the absorbency of different fabrics.
3. Justify the choice of material for an umbrella based on its properties.

Learning Objectives

• Classify common materials as either absorbent or waterproof based on experimental results.
• Design and conduct a simple experiment to compare the absorbency of different materials.
• Explain why a specific material is suitable for a particular purpose, such as a towel for drying or a raincoat for protection from rain.
• Analyze the properties of materials to justify their use in everyday objects like umbrellas or sponges.

Before You Start

Observing and Describing Materials

Why: Students need to be able to observe and describe basic characteristics of materials before they can investigate specific properties like absorbency.

Introduction to Solids and Liquids

Why: Understanding the basic states of matter, particularly liquids, is essential for conducting experiments involving water.

Key Vocabulary

Absorbent	A material that can soak up or absorb liquids. Absorbent materials have many small holes or spaces that can hold liquid.
Waterproof	A material that does not allow water to pass through it. Waterproof materials prevent liquids from soaking in.
Material	The substance or substances from which something is made. Examples include fabric, plastic, paper, and wood.
Property	A characteristic of a material that can be observed or measured, such as its absorbency or waterproofness.

Watch Out for These Misconceptions

Common Misconception

When something melts, it disappears or turns into 'nothing'.

What to Teach Instead

Weigh an ice cube, then weigh the water after it melts. Showing that the mass stays the same helps students understand that the material is still there, just in a different form. Active observation of the melting process is key.

Common Misconception

Mixing two things always creates a brand new material.

What to Teach Instead

Show a mix of sand and marbles. Students can see that the materials are just 'together' but haven't changed. Contrast this with mixing paint colors. This helps them distinguish between physical mixtures and more permanent changes.

Active Learning Ideas

Inquiry Circle: The Slime Lab

Students mix cornflour and water to create 'Oobleck'. They investigate how it acts like a solid when squeezed and a liquid when released, discussing how combining two simple materials created something with strange new properties.

40 min·Small Groups

Stations Rotation: Change Makers

Stations include: 1. Melting ice, 2. Scrunching/folding paper, 3. Mixing sand and water, 4. Stretching playdough. Students record if the change can be 'undone' (reversed) or if the material is changed forever.

40 min·Small Groups

Think-Pair-Share: The Chocolate Dilemma

Show a piece of melted chocolate and a solid piece. Ask pairs to discuss what happened and how they could turn the melted chocolate back into a solid. Share ideas about cooling and freezing with the class.

15 min·Pairs

Real-World Connections

• Clothing designers select waterproof fabrics like Gore-Tex for outdoor gear to keep hikers and skiers dry in wet conditions.
• The manufacturing of sponges relies on creating materials with high absorbency to effectively clean surfaces and soak up spills in kitchens and bathrooms.
• Builders choose waterproof membranes for roofing and foundations to protect buildings from water damage and mold.

Assessment Ideas

Exit Ticket

Provide students with three material samples (e.g., cotton cloth, plastic wrap, paper towel). Ask them to test each with a small amount of water and record on their card: 'Absorbent' or 'Waterproof' for each material, and one reason why.

Discussion Prompt

Present students with a scenario: 'Imagine you are designing a new pet bed. What material would you choose for the outer cover, and why? Would you want it to be absorbent or waterproof?' Facilitate a class discussion on their choices and reasoning.

Quick Check

Show students pictures of different objects (e.g., a beach towel, an umbrella, a paper napkin, a raincoat). Ask them to hold up a green card if the primary material is absorbent and a red card if it is waterproof. Discuss their answers.

Frequently Asked Questions

What is the difference between a physical and chemical change for Year 1?

At this level, we focus on 'reversible' versus 'irreversible'. A physical change like folding paper can be undone. A change like cooking an egg or burning wood cannot. Using the 'Can we get it back?' test is the best way for young students to categorize these changes.

How can active learning help students understand changing materials?

Active learning allows students to be the 'agents of change'. When they are the ones mixing, stirring, or freezing, they develop a sense of cause and effect. Collaborative investigations also allow them to compare their results with peers, which helps them see that scientific changes are predictable and repeatable.

What are some safe 'kitchen science' activities for Year 1?

Making playdough, melting ice with salt, mixing food coloring in water, or making 'fizzy' reactions with bicarb soda and vinegar are all safe and highly visual. These activities provide immediate feedback and are excellent for practicing observation skills.

How do Indigenous Australians use material changes?

Discuss the use of fire to change the properties of wood (making it harder for spears) or the use of water to leach toxins from bush foods like cycad nuts. This shows that changing materials is a sophisticated technology used for survival for thousands of years.