Materials and Their Properties

Overview

This unit introduces students to the science of materials. Students will explore the properties of solids, liquids, and gases, investigate reversible and irreversible changes, and learn how to separate mixtures. Through hands-on experiments and real-world investigations, students will understand how the properties of materials determine their uses and how materials can be transformed.

Key Concept

Change — Materials can change in observable ways. Understanding these changes helps us use materials effectively and responsibly.

Properties — The observable characteristics that distinguish different materials.
Evidence — The observations and data that help us understand what materials are and how they change.
Transformation — The process of changing materials from one form to another.

Global Context

Scientific and Technical Innovation — How does understanding materials help us create new products and solve problems?

Statement of Inquiry

The observable properties of materials determine how they can be used, changed, and reused.

Inquiry Questions

Factual Questions

What are the properties of solids, liquids, and gases?
What is the difference between reversible and irreversible changes?
How can mixtures be separated?

Conceptual Questions

How do the properties of a material make it suitable for certain uses?
What determines whether a change is reversible or irreversible?
How does heating and cooling change materials?

Debatable Questions

Is it always better to recycle materials than to create new ones?
Can we predict the properties of a new material without testing it?
Should plastic be banned completely?

ATL Skills

Thinking Skills

Observe and compare properties of different materials.
Classify changes as reversible or irreversible.
Analyse how properties determine the uses of materials.

Communication Skills

Describe materials and changes using scientific vocabulary.
Record observations clearly in lab notebooks.
Explain conclusions from experiments.

Research Skills

Design simple experiments to test material properties.
Record and organise experimental data.
Investigate how materials are used in everyday life.

Self-Management Skills

Follow safety procedures during experiments.
Handle materials and equipment responsibly.
Maintain organised experiment records.

Content

Week 1: Solids, Liquids and Gases

Properties of solids: fixed shape, fixed volume.
Properties of liquids: flow, take shape of container.
Properties of gases: fill space, no fixed shape.
Sorting and classifying materials by state.

Week 2: Properties of Materials

Observing properties: hardness, flexibility, transparency, strength.
Thermal and electrical conductivity.
Magnetic and non-magnetic materials.
Testing and comparing material properties.

Week 3: Heating and Cooling

How heating changes materials: melting, boiling, evaporation.
How cooling changes materials: freezing, condensation.
The role of temperature in material changes.
Investigating melting and boiling points.

Week 4: Reversible and Irreversible Changes

Reversible changes: melting, freezing, dissolving, evaporating.
Irreversible changes: burning, cooking, rusting, mixing.
Identifying and classifying changes.
Exploring chemical reactions safely.

Week 5: Dissolving and Separating Mixtures

What is dissolving? Solute, solvent, solution.
Factors affecting dissolving: temperature, stirring.
Separating mixtures: filtering, sieving, evaporation, magnetism.
Practical separation challenges.

Week 6: Materials in Our World

Why different materials are used for different purposes.
Natural vs. man-made materials.
Recycling and reusing materials.
Unit review and summative assessment.

Summative Assessment

Material Investigation Report: Students will investigate a common object and write a report explaining what materials it is made from, why those materials are suitable based on their properties, and whether more sustainable alternatives could be used.

Separation Challenge: Students will receive a mixture and must design and carry out a procedure to separate its components, recording their method, observations, and conclusions in a lab report.

Formative Assessment

Solid, liquid, gas sorting activities.
Material property testing and recording.
Reversible/irreversible change classification.
Dissolving experiments and observations.
Separation method matching exercises.
Quizzes on vocabulary and concepts.

Interdisciplinary Connections

Geography: Natural resources and where materials come from.
Design and Technology: Choosing materials for design projects.
Art: Exploring materials and their creative uses.
Mathematics: Measuring and comparing material properties.

Service as Action

Organise a recycling drive or waste audit at school.
Create educational materials about reducing, reusing, and recycling.
Investigate and report on single-use plastic use in the school.
Start a composting programme for organic waste.

IB Learner Profile

Inquirers: Students investigate materials through hands-on experiments.
Thinkers: Students analyse evidence to draw conclusions about properties and changes.
Knowledgeable: Students understand the properties and behaviours of different materials.
Caring: Students consider the environmental impact of material use.
Reflective: Students reflect on their own consumption and waste.

Self-Test

List three properties of solids, three of liquids, and three of gases.
What is the difference between a reversible and an irreversible change? Give an example of each.
What happens to chocolate when it is heated? Is this reversible?
How does filtering separate a mixture? What types of mixtures can it separate?
What is dissolving? Name the solute and solvent in a saltwater solution.
List three ways to speed up dissolving.
What is the difference between melting and dissolving?
How can you separate iron filings from sand?
Why are different materials used for different purposes? Give an example.
Explain why recycling is important for the environment.