lesson chem

1. Chemical and Physical Changes
• Understanding Matter Transformations
• Your Name | Subject | Grade Level

2. Lesson Objectives
• By the end of this lesson, students should be
able to:
• 1. Differentiate between physical and chemical
changes.
• 2. Identify real-life examples of physical and
chemical changes.
• 3. Explain the importance of these changes in
daily life.

3. What is a Physical Change?
• Definition: A physical change is a change in the
form or appearance of a substance without
altering its chemical composition.
• Key Characteristics:
• - No new substance is formed.
• - Usually reversible.
• - Changes in shape, size, or state of matter.

4. What is a Chemical Change?
• Definition: A chemical change occurs when
substances undergo a reaction and form a
new substance with different properties.
• Key Characteristics:
• - New substance is formed.
• - Usually irreversible.
• - Evidence includes color change, gas
production, temperature change, or
precipitation formation.

5. Key Differences Between Physical
and Chemical Changes
• Physical Change:
• - No new substance
• - Usually reversible
• - Example: Freezing water
• Chemical Change:
• - New substance formed
• - Rarely reversible
• - Example: Baking a cake

6. Identifying Changes (Activity)
• Look at the following images:
• - Crumpled paper
• - Burning candle
• - Dissolving sugar in water
• - Cooking rice
• Question: Are these physical or chemical
changes? Why?

7. Real-Life Applications
• - Cooking: Chemical changes occur when food
is cooked.
• - Weathering of Rocks: Physical and chemical
changes shape the Earth’s surface.
• - Recycling: Some materials undergo physical
changes (melting plastic) while others go
through chemical changes (composting
organic waste).

8. Summary
• - Physical changes affect form but not
composition.
• - Chemical changes create new substances.
• - Both types of changes are important in
nature and daily life.

9. Quiz Time! (Interactive)
• 1. Is melting ice a physical or chemical
change?
• 2. Is rusting metal a physical or chemical
change?
• 3. Is dissolving salt in water a physical or
chemical change?
• 4. What are signs of a chemical change?

10. Thank You!
• Any questions?
• Let’s discuss more examples!