Notes on Changes in Matter

Introduction

• Focus on physical and chemical changes in matter.
• Review from last week on properties like flammability, degradable, and biodegradable materials.

Objectives for the Lesson

1. Describe changes in matter involving physical and chemical changes.
2. Investigate how properties of materials change under extreme temperatures.
3. Identify beneficial phase changes.

Overview of Matter

• Definition: Matter is anything that has mass and takes up space.
• States of Matter: Solid, Liquid, and Gas.
• Examples: Air, food, atoms, and molecules are all forms of matter.

States of Matter

Solids

• Have a definite shape and volume.
• Particles are tightly packed in a regular pattern (crystal lattice).
• Example: Marbles, pebbles, rocks.

Liquids

• Have a fixed volume but take the shape of their container.
• Particles are close together but can move freely.
• Example: Water.

Gases

• Do not have a definite shape or volume.
• Fill the entire space available.
• Example: Air.

Changes in Matter

• Changes can be classified as physical or chemical depending on the impact on chemical composition.

Physical Changes

• Definition: Changes that affect one or more physical properties without altering chemical composition.
• Characteristics:
  • No new substances formed.
  • Changes in state (solid to liquid, liquid to gas, etc.).
  • Changes in appearance, texture, or shape can occur.

Examples of Physical Changes

• Melting: Solid to liquid (e.g., ice cream melting).
• Evaporation: Liquid to gas (e.g., water evaporating).
• Freezing: Liquid to solid (e.g., making ice cubes).

Real-Life Applications of Physical Changes

• Cooking: Melting butter for recipes.
• Recycling: Melting metals like aluminum to create new products.
• Art and Crafts: Melting crayons to create new shapes.

Chemical Changes

• Definition: Changes that result in the formation of new substances with different chemical compositions.
• Characteristics:
  • Formation of new substances.
  • Usually irreversible through simple physical processes.
  • Changes in properties such as color, taste, gas production, or precipitate formation.

Examples of Chemical Changes

• Combustion: Burning of materials resulting in ash, smoke, or gas.
• Rust Formation: Metal reacting with oxygen, creating rust.
• Baking: Ingredients changing chemically when baked.

Summary of Key Terms

• Melting: Solid to liquid.
• Evaporation: Liquid to gas.
• Freezing: Liquid to solid.
• Chemical Change: Formation of new substances.

Assessment

• Review questions at the end of the lesson to reinforce learning.
• Graphic organizer activity to summarize the types of changes in materials.

Conclusion

• Importance of understanding physical and chemical changes in daily life.
• Encouragement to continue exploring these concepts in future lessons.