Introduction to Chemistry I – SS1 Chemistry Lesson Note (First Term)

Chemistry is a branch of science that studies the nature, structure, composition, properties and uses of all forms of matter, and the changes in structure and composition that matter undergoes. It has three main branches: physical, organic and inorganic chemistry. It is applied in daily life and leads to many careers.

Behavioural objectives

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

• define science and chemistry;
• name the three main branches of chemistry and state what each deals with;
• list the steps of the scientific method;
• explain the terms hypothesis, theory and scientific law;
• state some applications of chemistry in everyday life;
• mention careers open to people who study chemistry.

What is chemistry?

Science is an organised body of knowledge gathered through systematic experimentation and philosophical observations.

Chemistry can be defined as a branch of science which deals with the study of the nature, structure, composition, properties and uses of all forms of matter and the changes in structure and composition which matter undergoes.

What are the branches of chemistry?

Chemistry is divided into three main branches, namely:

1. Physical chemistry deals with the physical aspects of chemistry, like quantum theory, heat and electricity.
2. Organic chemistry deals with the study of carbon and its compounds.
3. Inorganic chemistry deals with the study of elements, their properties and uses.

What are the steps of the scientific method?

The scientific method includes the following steps and stages:

1. Observation
2. Pattern
3. Problem
4. Hypothesis
5. Experiments
6. Theory
7. Law

Note: A hypothesis is a prediction or guess which explains an observed problem. When the hypothesis has been tested and found to be true within the limits of available evidence, it becomes a theory. A theory which has been extensively tested and proven correct without any exception becomes a scientific law.

What are the applications of chemistry?

Chemistry is applied in our everyday life as different activities take place in the environment. The effect of chemistry is felt in different aspects of life such as cooking, washing with soap or detergent, digestion of food and drugs. Other applications of chemistry include health care, transportation, food, houses and clothes.

What careers are open to people who study chemistry?

Chemistry is involved in our everyday lives and there is a vast range of careers open to those who have studied chemistry at any level. Great career opportunities exist both inside and outside the laboratory. You can choose a career from different fields such as:

1. Pharmaceutical/drug development
2. Science education
3. Chemical engineering
4. Mining and metallurgy
5. Pure and applied chemistry
6. Petroleum and petrochemical engineering
7. Quality control
8. Medicine and surgery
9. Chemical analysis/forensic science
10. Environmental chemistry
11. Science laboratory technology
12. Biochemistry, and others

Evaluation

1. Define chemistry.
2. Name the three main branches of chemistry and state what each deals with.
3. List the steps of the scientific method.
4. What is the difference between a hypothesis, a theory and a scientific law?
5. State four applications of chemistry in everyday life.

Assignment

1. State five applications of chemistry in our daily life.
2. Mention five adverse effects of chemicals and how they can be controlled.
3. Mention ten (10) career opportunities in chemistry.
4. List the branches of chemistry.