Pure Substances and Mixtures

Introduction

• Studying for an exam on pure substances and mixtures.
• Importance of understanding the difference between pure substances and mixtures.

Pure Substances

• Definition: Composed of one single type of matter or element.
• Properties: Have specific characteristics that don't change.
• Examples:
  • Water
  • Diamonds
• Physical Change:
  • The composition remains unchanged during physical changes.
  • Example: Freezing water to ice and melting back to water; still the same substance.

Mixtures

• Definition: Combination of two or more pure substances.
• Types of Mixtures:
  • Homogeneous Mixtures:
    • Components are not visible to the eye.
    • Examples:
      • Solutions like saltwater or chocolate milk.
      • Mayonnaise (made with eggs, oil, and salt).
  • Heterogeneous Mixtures:
    • Components are visible to the eye.
    • Example: Salad (tomato, lettuce, corn).

Classification Practice

• Chocolate Milkshake:
  • Classified as a homogeneous mixture (components not visible).
• Salad:
  • Classified as a heterogeneous mixture (components visible).

Conclusion

• Importance of understanding pure substances and mixtures for the exam.
• Encouragement to study more and practice classification of substances.