Class: Junior Secondary School 3 (JSS3, JSS 3)
Term: 1st Term
Week: 5
Age: 14 years
Duration: 45 minutes
Subject: Basic Science And Technology
Curriculum Theme: Basic Technology
Previous Lesson: Manufactured Boards, Wood Defects, and Preservation
Topic: Alloys
Subject Matter: Definition of alloy, Types of alloys, Properties and uses of alloys.

Specific Objectives

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

Cognitive Domain:
(a) Define alloy correctly.
(b) Identify and classify different types of alloys with examples.
(c) State the properties and uses of common alloys.
Affective Domain:
(a) Appreciate the importance of alloys in everyday life and industries.
Psychomotor Domain:
(a) Observe and differentiate between alloy samples and pure metals.
Social Domain:
(a) Work cooperatively in groups to identify examples of alloys and their uses.

Reference Materials

The following resources was used in planning this lesson:

9 Years Basic Education Curriculum
Lagos State Unified Scheme of work for Junior Secondary Schools
Britannica – “Alloy: Definition, Properties, and Examples” (https://www.britannica.com/science/alloy)
ThoughtCo – “Examples of Alloys and Their Composition” (https://www.thoughtco.com/examples-of-alloys-608261)
Relevant Textbooks

Instructional Materials

The teacher will teach this lesson with the aid of:

Samples or pictures of alloys such as bronze, brass, and steel
Chart showing pure metals and alloys
Metal objects like coins, keys, and cutlery
Whiteboard and markers
Video or picture slides of alloy production process

Rationale for the Lesson

This lesson enables pupils to understand how alloys are made, their properties, and how they improve the strength and usefulness of metals in daily applications.

Prerequisite/Previous Knowledge

Pupils already know about metals and their properties from previous lessons and can recognize common metal objects used in their environment.

Lesson Content/Board Summary

Alloys

Definition of Alloy

An alloy is a mixture of two or more metals, or a metal and another element, combined to improve strength, hardness, or resistance to corrosion. Alloys are made to achieve better properties than the original pure metals.

Examples include bronze (copper + tin), brass (copper + zinc), and steel (iron + carbon).

Types of Alloys

Alloys can be classified based on the type of metals they contain or their main component.

The following are the common types of alloys:

Ferrous Alloys: These alloys contain iron as the main metal. Examples are steel (iron and carbon) and stainless steel (iron, chromium, and nickel).
Non-Ferrous Alloys: These alloys do not contain iron. Examples are brass (copper and zinc), bronze (copper and tin), and duralumin (aluminium and copper).

Properties of Alloys

Alloys are made to possess special properties that make them more useful than pure metals.

The following are the main properties of alloys:

They are harder and stronger than pure metals.
They have better resistance to corrosion and rust.
They often have improved appearance and shine.
Some alloys are lighter in weight than pure metals.
They can withstand high temperatures.
They may conduct heat and electricity better in some cases.

Uses of Alloys

Alloys are used in different industries, tools, and everyday life due to their unique properties.

The following are the uses of some common alloys:

Bronze: Used for making statues, medals, and coins.
Brass: Used in musical instruments, electrical fittings, and decorations.
Steel: Used in building construction, vehicles, and machinery.
Stainless Steel: Used in cutlery, kitchen equipment, and hospital tools.
Duralumin: Used in making aircraft bodies due to its light weight.

Teaching Methods/Instructional Techniques:

Lecture, Discussion, Explanation, Demonstration, Question and Answer, Group Work, Use of Visual Aids

Instructional Procedures

To deliver this lesson, the teacher will adopt the following steps:

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: Teacher asks pupils to name objects made of metals around them and discusses their uses. Then introduces the lesson by showing samples of alloy materials.
Pupils’ Activity: Pupils mention metallic objects and observe the samples.
Learning Point: Pupils understand that metals can be combined to make stronger materials called alloys.

Step 2: Definition of Alloy

Time: 10 minutes
Teaching Skill: Explanation
Teacher’s Activity: Teacher defines alloy, explains how alloys are formed, and gives examples.
Pupils’ Activity: Pupils listen, ask questions, and note examples of alloys.
Learning Point: Pupils understand the meaning and composition of alloys.

Step 3: Types of Alloys

Time: 10 minutes
Teaching Skill: Discussion
Teacher’s Activity: Teacher explains the two main types of alloys (ferrous and non-ferrous) using examples and charts.
Pupils’ Activity: Pupils observe the chart, identify examples, and discuss the differences.
Learning Point: Pupils can distinguish between ferrous and non-ferrous alloys.

Step 4: Properties and Uses of Alloys

Time: 10 minutes
Teaching Skill: Explanation and Demonstration
Teacher’s Activity: Teacher lists and discusses the properties of alloys, shows alloy samples, and explains their uses in daily life.
Pupils’ Activity: Pupils observe, listen, and mention items made from alloys.
Learning Point: Pupils understand the major properties and uses of common alloys.

Step 5: Note-Taking

Time: 5 minutes
Teaching Skill: Explanation
Teacher’s Activity: Teacher writes the summary of the lesson on the board for pupils to copy.
Pupils’ Activity: Pupils copy the notes neatly into their exercise books.
Learning Point: Pupils retain key points of the lesson in written form.

Step 6: Evaluation/Review

Time: 3 minutes
Teaching Skill: Questioning
Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

What is an alloy?
Mention two types of alloys with examples.
State three properties of alloys.
Give two uses of alloys.
Pupils’ Activity: Pupils respond to the questions orally.
Learning Point: Pupils demonstrate understanding of the lesson objectives.

Step 7: Conclusion

Time: 2 minutes
Teaching Skill: Reinforcement
Teacher’s Activity: Teacher summarizes the lesson, corrects errors, and emphasizes the usefulness of alloys in modern life.
Pupils’ Activity: Pupils listen attentively and ask questions where necessary.
Learning Point: Pupils appreciate the importance of alloys in improving metal performance.

Lesson Keywords

Alloy – mixture of two or more metals
Ferrous – containing iron
Non-Ferrous – not containing iron
Corrosion – gradual destruction of metals by chemical reaction
Durability – ability to last long without damage

Differentiation

Teacher supports slower learners with repeated explanations and visual demonstrations, while advanced learners are given additional examples and tasked to research new alloys.

Note for teachers using this lesson plan

Use real samples where possible to make the lesson practical. Emphasize safety when handling metals and encourage pupils to explore more examples in their environment.