Classify mixtures

Hierarchy and Classification of Matter

  • Fundamental Decision Tree for Matter:

    • Question 1: Does the matter have constant properties and constant composition?

    • NO: It is a Mixture.

      • Question 2: Is it uniform throughout?

      • NO: It is a Heterogeneous Mixture (a mixture that is not uniform throughout).

      • YES: It is a Homogeneous Mixture (a mixture that is uniform throughout, also classified as a Solution).

    • YES: It is a Pure Substance.

      • Question 2: Can it be simplified chemically?

      • YES: It is a Compound (a pure substance that can be broken into simpler substances by chemical means).

      • NO: It is an Element (cannot be simplified chemically; consists of one atom present / one type of atom, and can be found on the Periodic Table).

Physical vs. Chemical Separations and Changes

  • Separation of Solid-Liquid Mixtures:

    • Filtration: The primary method used for the separation of a solid-liquid mixture.

  • Physical Separability Criterion:

    • If a sample of matter (such as a liquid in a jar) can be separated by physical means, it is definitively classified as a mixture.

  • Physical Change Example:

    • When a white powder is placed in water, where some of the powder sinks and some arises, this separation behavior serves as an example of a physical change.

  • Chemical Breakdown Criterion:

    • A pure substance that can be broken down into simpler substances by chemical means is a compound.

Categorized Examples of Matter

  • Elements:

    • Defined by having one atom present.

    • Can be found listed in the Periodic Table.

  • Compounds:

    • A pure substance made of two or more different elements that are chemically joined together in a fixed ratio.

      • Glucose: Classified specifically as a compound.

  • Homogeneous Mixtures (Solutions):

    • Uniform in appearance and composition throughout.

      • Gasoline: Classified specifically as a solution / homogeneous mixture.

  • Heterogeneous Mixtures:

    • Non-uniform composition throughout.

      • Italian dressing: Classified specifically as a heterogeneous mixture.