1. Mixtures and Pure Substances

2. A pure substance is a material whose properties are not a blend and are always the same. Ex: Gold, silver, sugar, and salt. Pure substances must be homogeneous.

3. Mixtures and Pure Substances All homogeneous materials are not pure substances. In order to determine if it is a pure substance, we must investigate the properties of the material to find out if they are always the same.

4. Mixtures and Pure Substances If the properties are always exactly the same in all parts of the material, no matter what part of the world the material comes from, then you may infer (assume) that you have a pure substance. A thorough investigation is necessary before anything can be classified as a pure substance.

5. Summary 1. All materials can be classified as heterogeneous or homogeneous. 2. Homogeneous materials can be further classified as solutions or pure substances.

6. All Materials Heterogeneous MaterialsHomogeneous Materials Solutions (Homogeneous mixtures) Pure substances