Energy – JSS1 Basic Science Lesson Note (Second Term)

Energy is the ability or capacity to do work. Its unit is the joule (J). Energy comes from natural sources such as the sun, wind and water, and from artificial sources such as batteries and generators. It exists in forms such as light, sound, heat, chemical, electrical and mechanical energy, and it can change from one form to another.

Behavioural objectives

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

• define energy and state its unit;
• list natural and artificial sources of energy;
• name the forms of energy;
• state the Law of Conservation of Energy;
• give examples of energy conversion and everyday uses of energy.

What is energy?

Energy is defined as the ability or capacity to do work. The unit of energy is the joule (J).

What are the sources of energy?

There are two main sources of energy: natural and artificial sources.

Natural sources of energy

• Sun
• Food
• Natural gas
• Coal
• Wind
• Crude oil
• Wood
• Water

Artificial sources of energy

• Batteries
• Electrical generators
• Petroleum products (e.g. diesel, kerosene, etc.)

What are the forms of energy?

1. Light energy
2. Sound energy
3. Heat energy
4. Chemical energy
5. Electrical energy
6. Mechanical energy (potential and kinetic energy)

How is energy transformed?

Energy can be converted or transformed from one form to another. This is governed by the Law of Conservation of Energy, which states that:

Energy can neither be created nor destroyed, but it can be converted from one form to another.

Examples of energy conversion

1. Electrical energy → Heat energy: pressing iron, boiling ring, etc.
2. Electrical energy → Light energy: bulb, television, etc.
3. Chemical energy → Electrical energy: battery, etc.
4. Electrical energy → Kinetic energy: fan, etc.
5. Electrical energy → Sound energy: electric bell, telephone earpiece, etc.
6. Mechanical energy → Light energy: bicycle dynamo
7. Sound energy → Electrical energy → Sound energy: telephone

What is energy used for?

Energy is used in our daily activities such as:

• Walking
• Cooking
• Playing
• Operating appliances
• Running
• Household work

Evaluation

1. Define energy.
2. Mention five (5) forms of energy.
3. State the Law of Conservation of Energy.
4. Give two examples of energy conversion.

Assignment

1. List four natural sources of energy.
2. List two artificial sources of energy.