Chapter 2: Matter and Change

1. Chapter 2: Matter and Change Elements and compounds

2. Learning Target You will: • Classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

3. Matter Concept Map You will classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

4. Continued … You will classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

5. Continued … You will classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

6. Pure Substance vs. Mixture • Pure substance: cannot be separated further by physical means • Mixture: can be separated by physical means You will classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

7. Element vs. Compound • Element: cannot be separated into simpler substances • Example: mercury • Can see on the periodic table • Compound: atoms of different elements chemically combined • Example: mercury sulfide • Must be chemically taken apart You will classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

8. Continued … You will classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

9. Homogeneous vs. Heterogeneous • Homogeneous: the same throughout • Example: stainless steel • Heterogeneous: not the same throughout • Example: granite You will classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

10. Practice • Classify each of the following types of matter as an element, a compound, or a mixture and provide reasons for their answers. • Epsom salt (magnesium sulfate) • Hydrogen peroxide (H2O2) • Mercury (Hg) • Sweetened iced tea • Compound; it is composed of at least two elements. • Compound; it is composed of two elements. • Element; its symbol shows that it is composed of only one kind of matter. • Mixture; it has a composition that can vary. You will classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

11. Separation techniques Electrolysis Filtration Distillation separation process water is boiled off, changed to steam, and leaves a precipitate. steam is collected & cooled, condensing to pure water. using an electric current to drive a non-spontaneous chemical reaction can be used to separate compounds. Separates a liquid from a solid Liquid passes through filter paper and solid remains You will classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

12. Examples • Liquid A and Liquid B are clear liquids. They are placed in open containers and allowed to evaporate. When evaporation is complete, there is a white solid in container B but no solid in container A. From these results, what can you infer about the two liquids? • Liquid A is probably a substance. Liquid B is a mixture. • A clear liquid in an open container is allowed to evaporate. After three days, a solid is left in the container. Was the clear liquid an element, a compound, or a mixture? How do you know? • The liquid was not an element because a solid was left when the liquid evaporated. A physical process, such as evaporation, cannot be used to break down a compound. Therefore, the liquid was a mixture. You will classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

13. You try … In your notebook, design an experiment that employs all the separation techniques mentioned. You will classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.

14. Summarize how you feel … You will: • Classify whether matter is a pure substance, element, compound, mixture, solution, heterogeneous or homogeneous.