Class: Junior Secondary School 2 (JSS 2)
Term: 3rd Term
Week: 5
Age: 13 years
Duration: 45 minutes
Subject: Basic Science and Technology
Curriculum Theme: Basic Science
Previous Lesson: Abstinence: Meaning of Abstinence.
Topic: CHEMICALS
Subject Matter: Meaning of chemicals, Classes of chemicals Based on use: Pharmaceutical/cosmetics, Nuclear, Agrochemical, Industrial, Laboratory, Based on hazardous nature, Highly hazardous and toxic: Non-hazardous and toxic

Specific Objectives

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

Cognitive Domain:

Define chemicals.
List classes of chemicals based on their use.
List classes of chemicals based on their hazardous nature.

Affective Domain:

Appreciate the importance of safe handling of chemicals.
Recognize the benefits of chemicals in various sectors.

Psychomotor Domain:

Identify various chemicals found in their environment.
Differentiate between hazardous and non-hazardous chemicals.

Advocate for responsible use and disposal of chemicals in their community.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum
State Unified Scheme of Work
Basic Science and Technology for Junior Secondary Schools Book 2
https://www.who.int/news-room/fact-sheets/detail/chemicals-and-health
https://www.epa.gov/chemicals-under-tsraca

Instructional Materials

The teacher will teach this lesson with the aid of:

Charts showing different classes of chemicals and their uses.
Pictures of chemical warning signs.
Samples of common chemicals (e.g., salt, sugar, soap, fertilizer in small, labelled containers).

Rationale for the Lesson

This lesson helps pupils understand what chemicals are and their various uses in daily life. It also teaches them to identify hazardous chemicals and the importance of handling them safely to prevent harm to themselves and the environment.

Prerequisite/Previous Knowledge

Pupils should have basic knowledge of substances and their properties from previous science lessons.

Lesson Content/Board Summary

CHEMICALS

Meaning of Chemicals

Chemicals are substances that have a definite composition and distinct properties. They are found everywhere around us, both naturally and artificially produced. Everything around us, including air, water, and our bodies, is made up of chemicals.

Classes of Chemicals Based on Use

Chemicals can be classified into different categories based on their primary uses:

Pharmaceutical/Cosmetics: These are chemicals used in making medicines, drugs, and beauty products. Examples include paracetamol, antibiotics, creams, and lotions.
Nuclear: These chemicals are involved in nuclear reactions, often used for energy generation or in weapons. Examples include uranium and plutonium.
Agrochemical: These are chemicals used in agriculture to improve crop yield or protect crops from pests. Examples include fertilizers, pesticides, and herbicides.
Industrial: These chemicals are used in various manufacturing processes to produce goods like plastics, paints, textiles, and cleaning agents. Examples include sulfuric acid, caustic soda, and petroleum products.
Laboratory: These are chemicals used for experiments, research, and analysis in scientific laboratories. Examples include reagents like litmus paper, acids, and bases.

Classes of Chemicals Based on Hazardous Nature

Chemicals can also be classified based on how dangerous they are to human health and the environment:

Highly Hazardous and Toxic Chemicals: These chemicals can cause severe harm, illness, or death even in small amounts. They can also be corrosive, flammable, explosive, or reactive. They require careful handling, storage, and disposal. Examples include strong acids (e.g., concentrated sulfuric acid), mercury, cyanide, and certain pesticides.
Non-Hazardous and Non-Toxic Chemicals: These chemicals are generally safe and do not pose a significant risk to health or the environment under normal use. They are usually stable and do not react dangerously. Examples include common salt (sodium chloride), sugar, water, and many food additives.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to name some common substances they use daily.
Pupils’ Activity: Pupils respond by naming substances like water, salt, sugar, soap.
Learning Point: Pupils recall prior knowledge and are introduced to the concept of substances.

Step 2: Meaning of Chemicals

Time: 8 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher explains the meaning of chemicals, emphasizing that everything is made of chemicals, both natural and man-made.
Pupils’ Activity: Pupils listen attentively and take notes on the definition of chemicals.
Learning Point: Pupils understand the fundamental definition of chemicals.

Step 3: Classes of Chemicals Based on Use

Time: 10 minutes
Teaching Skill: Classification/Illustration
Teacher’s Activity: The teacher introduces and explains the different classes of chemicals based on their use, using charts and examples.
Pupils’ Activity: Pupils identify and list the classes of chemicals based on use as explained by the teacher.
Learning Point: Pupils learn how chemicals are categorized by their applications.

Step 4: Examples of Chemicals (Use-based)

Time: 7 minutes
Teaching Skill: Examples/Discussion
Teacher’s Activity: The teacher provides specific examples for each use-based class (e.g., paracetamol for pharmaceutical, fertilizer for agrochemical) and encourages pupils to suggest more.
Pupils’ Activity: Pupils discuss the examples and contribute additional examples based on their knowledge.
Learning Point: Pupils connect theoretical classifications to real-world examples.

Step 5: Classes of Chemicals Based on Hazardous Nature

Time: 5 minutes
Teaching Skill: Explanation/Differentiation
Teacher’s Activity: The teacher explains the classification of chemicals based on their hazardous nature: highly hazardous/toxic and non-hazardous/non-toxic.
Pupils’ Activity: Pupils listen and understand the difference between hazardous and non-hazardous chemicals.
Learning Point: Pupils begin to differentiate chemicals based on safety.

Step 6: Examples of Hazardous Chemicals and Safety

Time: 5 minutes
Teaching Skill: Demonstration/Safety Awareness
Teacher’s Activity: The teacher shows pictures of warning signs and gives examples of hazardous chemicals, stressing the importance of safe handling and storage.
Pupils’ Activity: Pupils observe the warning signs and discuss the dangers associated with hazardous chemicals.
Learning Point: Pupils become aware of the risks and the need for safety when handling chemicals.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

What are chemicals?
List three classes of chemicals based on their use.
Give two examples of highly hazardous chemicals.
Differentiate between highly hazardous and non-hazardous chemicals.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 3 minutes
Teaching Skill: Summarization/Homework
Teacher’s Activity: The teacher summarizes the main points of the lesson and gives homework. Homework: Research and list five common household chemicals and classify them as hazardous or non-hazardous.
Pupils’ Activity: Pupils listen to the summary and copy the homework.
Learning Point: Pupils reinforce their learning and prepare for further study.

Lesson Keywords

Chemicals – Substances with definite composition and properties.
Hazardous – Dangerous, risky, or harmful.
Toxic – Poisonous, capable of causing harm or death.
Pharmaceutical – Relating to medicinal drugs.
Agrochemical – Chemicals used in agriculture.

Differentiation

For pupils who grasp concepts quickly, the teacher can ask them to identify chemical warning symbols and explain their meanings. For those who need more support, the teacher will provide simplified definitions and more direct examples, possibly using visual aids extensively and allowing peer-assisted learning.

Note for teachers using this lesson plan

Ensure to handle any chemical samples with extreme care, preferably using only non-hazardous common household items for demonstration. Emphasize safety precautions and the importance of never tasting or directly smelling unknown chemicals. Encourage pupils to look for safety labels on products at home.