Basic Science and Technology - Junior Secondary 2 - Kinetic theory I

TERM: 2^ND TERM

WEEK: 6

CLASS: Junior Secondary School 2

AGE: 13 years

DURATION: 40 minutes each for 2 periods

DATE:

SUBJECT: Basic Science

TOPIC: Kinetic theory I

SPECIFIC OBJECTIVES: At the end of the lesson, the learners should be able to

1. ) Define the Kinetic theory of matter
2. ) Outline the molecular structure of solids, liquids and gases

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, story-telling, videos from source

INSTRUCTIONAL MATERIALS: Recommended Basic Science textbooks for Junior Secondary School 2

INSTRUCTIONAL PROCEDURES: PERIOD 1-2:

NOTE

KINETIC THEORY

The Kinetic Theory of Matter states that all matter is made up of small particles (atoms, molecules, or ions) that are in constant motion. The behavior of these particles determines the properties of the substance, such as temperature, pressure, and volume. According to the theory, the motion of particles is faster at higher temperatures, and the strength of the forces between particles determines the state of matter (solid, liquid, or gas). The main postulates of the Kinetic Theory of Matter include:

• Matter is made of tiny particles.
• These particles are in constant random motion.
• The particles are in constant collision with each other and the walls of the container (in the case of gases).
• The energy of particles depends on the temperature.

Molecular Structure of Solids, Liquids, and Gases:

Solids:

• The molecules in solids are tightly packed together in a regular arrangement.
• The particles vibrate in place but do not move from their fixed positions.
• Solids have a definite shape and volume because the particles are closely bound by strong intermolecular forces.
• The particles in solids have low kinetic energy, and the forces between them are stronger than in liquids and gases.

Liquids:

• In liquids, the molecules are still close together but not in a fixed arrangement. They can move past one another.
• Liquids have a definite volume but no definite shape; they take the shape of the container they are in.
• The intermolecular forces in liquids are weaker than those in solids but stronger than in gases.
• The particles in liquids have more kinetic energy than in solids but less than in gases.

Gases:

• The molecules in gases are far apart and move freely at high speeds.
• Gases have neither a definite shape nor a definite volume. They expand to fill the container they are in.
• The intermolecular forces in gases are very weak, which allows the particles to move independently.
• The kinetic energy of gas particles is much higher than that of solids and liquids, and this increased motion explains the properties of gases.

EVALUATION:

1. What is the Kinetic Theory of Matter, and how does it explain the behavior of particles in different states of matter?
2. How do the molecular structures of solids, liquids, and gases differ in terms of particle arrangement and movement?
3. Explain why solids have a definite shape and volume, while liquids and gases do not.
4. Describe the relationship between the temperature of a substance and the kinetic energy of its particles.
5. In terms of the Kinetic Theory, why does a gas expand to fill its container, while a liquid only takes the shape of its container but does not expand to fill it completely?

CLASSWORK: As in evaluation

CONCLUSION: The teacher marks their books and commends them positively