ELEMENTS, COMPOUNDS AND MIXTURES

PlantUML DiagramPlantUML Diagram

Classification of Matter

I. Classification of Matter

A. Pure Substances

  • 1. Elements
  • 2. Compounds

B. Mixtures

  • 1. Homogeneous
  • 2. Heterogeneous
    • a. Colloid
    • b. Suspension

    Colloids, Emulsions, and Suspensions

    1. Colloid

    Definition: A substance with microscopic particles dispersed in a medium, not dissolved.

    Characteristics:

    • Dispersed particles do not settle or form sediment if left undisturbed.

    Example: Pumice (air particles dispersed in solid stone).

    2. Emulsion

    Definition: A specific type of colloid.

    Characteristics:

    • Microscopic particles of liquid dispersed in another liquid.

    Example: Milk (lipophilic butterfat particles dispersed in a water-based medium).

    3. Suspension

    Definition: Similar to a colloid, but with larger dispersed particles.

    Characteristics:

    • Dispersed particles will eventually settle or form sediment.

    Example: Sand in water (when shaken, sand disperses; when left alone, it settles at the bottom).

    ## Key Differences

    • Particle Size:
      • Colloids and Emulsions: Microscopic particles
      • Suspensions: Larger particles
    • Settling Behavior:
      • Colloids and Emulsions: Do not settle
      • Suspensions: Will settle over time
    • Medium:
      • Colloids: Any medium (solid, liquid, or gas)
      • Emulsions: Specifically liquid in liquid
      • Suspensions: Typically solid in liquid

II. Elements

A. Definition

Simplest form of matter made up of the same type of atoms.

B. Characteristics

  • 1. Consist of atoms with the same atomic number (proton number).
  • 2. Cannot be broken down through chemical means.

C. Physical vs. Chemical Changes

  • 1. Physical change: Alters physical properties.
  • 2. Chemical change: Forms a new substance.

III. Compounds

A. Definition

Substance formed when two or more different atoms chemically combine.

B. Key Points

  • 1. Result of a chemical reaction.
  • 2. New substance with properties different from constituent elements.

IV. Mixtures

A. Definition

Substance formed when two or more substances physically combine.

B. Characteristics

  • 1. Does not contain the same types of particles.
  • 2. Particles have different chemical compositions.

C. Example

Tea (combination of milk, water, tea leaves, and sugar).

V. Properties of Matter

  • A. Physical properties
  • B. Chemical properties