PSc.2.1 OBJECTIVE: Understand types, properties and structure of matter.

1. PSc.2.1 OBJECTIVE: Understand types, properties and structure of matter.

2. Objectives PSc.2.1.1 Classify matter as: homogeneous or heterogeneous; pure substance or mixture; element or compound; metals, nonmetals or metalloids; solution, colloid or suspension.

3. Shoe Classification Activity

4. Matter Flowchart MIXTURE PURE SUBSTANCE yes no yes no Is the composition uniform? Can it be chemically decomposed? Colloids Suspensions MATTER Can it be physically separated? yes no Heterogeneous Mixture Homogeneous Mixture (solution) Compound Element

5. Homogeneous vs Heterogeneous If matter is not uniform throughout, then it is a heterogeneous. If matter is uniform throughout, it is homogeneous.

6. Homogeneous Matter Salt water, apple juice and dust free air (mixture of nitrogen, oxygen, argon, carbon dioxide, water vapor and other gases) are examples of homogeneous materials.

7. Homogeneous Matter Brass (solid mixture of copper and zinc) is also homogeneous. Brass is an alloy, which is a mixture of metals.

8. Heterogeneous Matter Oil-and-vinegar salad dressing, which has a layer of oil floating on a layer of vinegar, is heterogeneous.

10. Homogeneous vs. Heterogenous Matter • Classify the following substances and mixtures as either homogeneous or heterogeneous. • Flat soda pop, cherry vanilla ice cream, salad dressing, sugar, soil, aluminum foil, black coffee, sugar water, city air, paint, alcohol, iron, beach sand, pure air, spaghetti sauce.

11. Homogeneous vs. Heterogeneous Matter Homogeneous Heterogenous Cherry vanilla ice cream Salad dressing Soil City air Paint Beach sand Spaghetti sauce • Sugar • Aluminum foil • Black coffee • Sugar water • Iron • Pure air • Alcohol • Flat soda pop

12. Pure Substances A pure substance always has the same composition. Pure substances are either elements or compounds.

13. Elements are substances that cannot be broken down into other substances chemically or physically. Examples include sodium, carbon and gold. Elements

14. Elements Elements composed of identical atoms Ex: copper wire, aluminum foil

15. Compounds Compound composed of 2 or more elements in a fixed ratio properties differ from those of individual elements Ex: table salt

16. Another example of a compound includes water (hydrogen and oxygen). Compounds

17. Mixtures A mixture can be defined as something that has variable composition. Soda is a mixture (carbon dioxide is dissolved in it), and coffee is a mixture (it can be strong, weak or bitter).

18. Heterogeneous Mixtures A heterogeneous mixture contains regions that have different properties from those of other regions. When we pour sand into water, the resulting mixture contains two distinct regions.

19. Homogeneous Mixtures Homogeneous mixtures (also known as solutions) are mixtures in which the composition is uniform, there are no chunks or layers.

20. Substances vs. Mixtures • Classify the following as to whether it is a substance or a mixture. • Sodium, water, soil, coffee, oxygen, alcohol, carbon dioxide, cake batter, air, soup, iron, salt water, ice cream, nitrogen, eggs, blood, table salt, nail polish, milk, cola

21. Substances vs. Mixtures Substances Mixtures Soil Coffee Cake batter Air Soup Salt water Ice cream Eggs Blood Nail polish Milk Cola Alcohol • Sodium (Na) • Water (H2O) • Oxygen (O2) • Carbon Dioxide (CO2) • Iron (Fe) • Nitrogen (N2) • Table Salt (NaCl)

22. Identification Activity • Classify the contents of each bag as an element, compound, or mixture. • Justify your answers.

23. Pure Substances and Mixtures

24. Question Classify each of the following as a pure substance, a homogeneous mixture or a heterogeneous mixture. A. gasoline homogeneous mixture B. copper metal pure substance

25. Question Classify each of the following as a pure substance, a homogeneous mixture or a heterogeneous mixture. C. a stream with gravel at the bottom heterogeneous mixture D. chunky peanut butter heterogeneous mixture

26. Question Classify each of the following as a pure substance, a homogeneous mixture or a heterogeneous mixture. E. a multivitamin tablet homogeneous mixture F. carbon dioxide gas pure substance

27. Quiz • _____ has mass and occupies space. • Elements _____ be broken down into simpler substances. • Pure substances include _____ and _____. • The formula H2O formula represents a _____ of water. • Mixtures are formed from _____ substances.

28. Tyndall Effect The Tyndall Effect is light scattering by particles in a colloid or particles in a fine suspension. Tyndall Effect The Tyndall Effect is shown on the left.

30. Mixtures Solution homogeneous very small particles no Tyndall effect particles don’t settle Ex: rubbing alcohol

31. Colloid heterogeneous medium-sized particles Tyndall effect particles don’t settle Ex: milk Mixtures

32. Suspension heterogeneous large particles Tyndall effect particles settle Ex: fresh-squeezed lemonade Mixtures

33. A) mayonnaise Question Classify each of the following as a solution, colloid or suspension. colloid B) muddy water suspension

34. C) fog Question Classify each of the following as a solution, colloid or suspension. colloid D) salt water solution

35. E) Italian salad dressing Question Classify each of the following as a solution, colloid or suspension. suspension

36. Quiz • A difference in what physical property is often used to separate two immiscible liquids? • Fog and smoke are examples of what type of heterogeneous mixture? • What is another term for a homogeneous mixture? • What is an alloy?

37. Quiz • The temperature at which a solid becomes a liquid. • Ability of a substance to burn in the presence of oxygen. • Ability of a substance to combine chemically with another substance. • Mass per unit volume of a substance. • Melting point • Boiling point • Density • Reactivity • Flammability