Basic 2 · Science · Materials

Properties of Materials

In this topic you will describe materials as hard or soft, rough or smooth, transparent or opaque, and bendable or not.

By the end of these notes you should be able to:

Describe materials using properties
Test materials for these properties
Group materials by their properties

What you already know

Materials around us (Basic 1)

Copy everything that has a blue line on its left into your notebook. The other parts are for reading.

Strand: Diversity of Matter
Sub-strand: Materials
Indicator: B2.1.2.1.1 – Know the common properties of materials such as soft hard rough smooth opaque transparent, bendable

Introduction

A window is made of glass because we can see through it. A door is made of wood because it is strong and we cannot see through it. Materials have different properties.

1. What is a Property?

Property: What a material is like, such as hard or soft.

2. Common Properties

Properties of materials

Property	Meaning	Example
hard	does not change shape when pressed	stone, metal
soft	easy to press	cotton wool, sponge
rough	bumpy	sandpaper, tree bark
smooth	even	glass, plastic
transparent	you can see through it	clear glass, clear plastic
opaque	you cannot see through it	wood, cardboard
bendable	can bend without breaking	rubber, paper

Looking through a clear bottle and through a piece of wood — Figure 1: Transparent and opaque Draw one transparent and one opaque thing.Illustration: Sirbus

Tip: Test by touching, pressing, bending and looking through.

New words

property: What a material is like.
transparent: Can be seen through.
opaque: Cannot be seen through.
bendable: Can bend without breaking.

Summary

Materials have properties like hard, soft, rough and smooth.
Transparent materials let us see through; opaque ones do not.
We test materials by touching, pressing, bending and looking.

Class activity: Material Tests

Take the wood, metal spoon and clear plastic bottle.
Press, bend and look through each one.
Record each property in a table.

You need: Wood offcut, Metal spoon, Clear plastic bottle

Exercises

Answer in your exercise book first, then check your answers.

1. Which material is transparent?
- A. Clear glass
- B. Wood
- C. Stone
- D. Cardboard
Show answer
Answer: Clear glassWe can see through it.
2. Which material is soft?
- A. Cotton wool
- B. Metal
- C. Stone
- D. Glass
Show answer
Answer: Cotton woolIt is easy to press.
3. Wood is opaque.
- A. True
- B. False
Show answer
Answer: TrueWe cannot see through wood.
4. Stone is bendable.
- A. True
- B. False
Show answer
Answer: FalseStone breaks; it does not bend.
5. Bumpy materials are ______.
Show answer
Answer: roughRough means bumpy.
6. Why are windows made of glass?
Show answer
Answer: Glass is transparent so light can come in and we can see out.Glass lets us see through.

Homework

Find three materials at home. Write one property of each.