1. Classifying Matter Section 2.1

2. Why do we classify? Classifying helps us understand the properties of a certain material Example: We separate laundry because fabrics react differently when they are washed a certain way.

3. How do we classify? Look at the composition and characteristics of materials and place them in separate categories.

4. Think of a way to classify the following items : Pencil Banana School Bus Fire engine Red marker Apple

5. How did you classify them? By color? (red and yellow) By function? (food, writing tool, or vehicles) We need to have a standard way to classify matter This helps us understand and remember physical and chemical properties

6. Matter Matter is anything that takes up space Matter can be classified in several different ways. 1.Solid, liquid, gas, or plasma 2.Metal, nonmetal, or metalloid 3.Acid, base, or salts 4.Elements, compounds, suspension, solution, colloid, or mixture

7. For this chapter, we are classifying into the last of those four (Elements, compounds, suspension, solution, colloid, or mixture)

8. Matter

9. Matter can be divided into two categories All matter is either a substance or a mixture Matter that always has the same composition is known as a pure substance (or just substance) Matter that has varying amounts of different things is known as a mixture

10. Matter Substance Mixture

11. Substances can be divided into two categories Elements are substances that are pure and only have one type of atom –Examples: H, C, O, (anything found on the periodic table of elements) Compounds are substances made from two or more different types of atoms –Examples: NaCl (salt), H 2 O (water), CO 2 (carbon dioxide)

12. Matter Substance Mixture ElementCompound

13. Elements and Compounds can be further classified (You won’t be tested on this, because it isn’t in your book...but it might show up as a bonus question) Elements can either be metal, nonmetal, or metalloid Compounds can be organic (contain Carbon) or inorganic (don’t contain Carbon)

14. Matter Substance Mixture ElementCompound

15. Mixtures The properties of mixtures vary because the composition of a mixture is not fixed Example: Think of a chili recipe

16. Matter Substance Mixture ElementCompound Heterogeneous Mixture Homogeneous Mixture

17. Mixtures can be classified into two groups All mixtures are either heterogeneous or homogeneous mixtures A heterogeneous mixture has parts that are noticeably different from one another A homogeneous mixture has multiple parts that are so evenly mixed, it is difficult to distinguish one substance from another.

18. Some heterogeneous mixtures can be classified as suspensions A suspension is a heterogeneous mixture that separates or layers over time These are things that would be easy to filter Example: Italian salad dressing

19. Matter Substance Mixture ElementCompound Heterogeneous Mixture Homogeneous Mixture Suspension Heterogeneous Mixture

20. Homogeneous Mixtures can be classified into two groups Colloids are homogeneous mixtures that have particles large enough to scatter light, but not enough to filter and separate Example: Fog is a colloid Solutions are mixtures that form when substances dissolve and form a homogeneous mixture Example: salt water

21. Matter Substance Mixture ElementCompound Heterogeneous Mixture Homogeneous Mixture Suspension Heterogeneous Mixture SolutionColloid

22. End of notes for today

23. Flip your paper over and complete the flow chart on the back There are a series of questions you can ask yourself to figure out how to classify something

24. To find out if it is a substance or a mixture ask this question: Does it have a fixed and uniform composition? (Is it the same every time?) Yes – means it is a substance No – means it is a mixture

25. Matter Substance Mixture

26. If it is a substance: Now ask: Is there more than one type of atom? Yes – means it’s a compound No – means it’s an element

27. Matter Substance Mixture ElementCompound

28. Now, let’s pretend it does NOT have a fixed uniform composition… Would it be a substance or a mixture? It would be a mixture! Now ask another question to see if it is homogeneous or heterogeneous Question: Are the substances noticeably different? –Yes : means it is a heterogeneous mixture –No: means it is a homogeneous mixture

29. Matter Substance Mixture ElementCompound Heterogeneous Mixture Homogeneous Mixture

30. Let’s pretend it had noticeably different parts We need to determine if the heterogeneous mixture is a suspension or just a heterogeneous mixture Ask this Question: Do the particles layer or separate over time? Yes – means it is a suspension No – means it is still just a heterogeneous mixture

31. Matter Substance Mixture ElementCompound Heterogeneous Mixture Homogeneous Mixture Suspension Heterogeneous Mixture

32. Now, go back and pretend that the Mixture was NOT noticeably different What is it? It is a homogeneous mixture! Ask a question to classify it further: Can light clearly pass through it? Yes – means it is a solution No – means it is a colloid

33. Matter Substance Mixture ElementCompound Heterogeneous Mixture Homogeneous Mixture Suspension Heterogeneous Mixture SolutionColloid

34. Use your flowchart to classify Sugar Dirt Carbon Polluted water Aluminum Milk (this one is tricky) Table salt (NaCl) Pizza Italian salad dressing Air Hydrogen

35. Use your flowchart to classify 1.Copper 2.Lemonade 3.Smoke 4.Ice cream sundae 5.Helium 6.Hydrogen Peroxide (H 2 O 2 ) 7.Sugar Water 8.Blue Gatorade 9.Beach sand 10.Ethanol (C 2 H 5 OH ) 11.Garden Salad 12.Muddy water 13.Silicon 14.Gasoline floating on top of a puddle