1. Chemistry Do-now  Hand in lab questions on my front desk  In your notes:  Define mass and volume  If an object’s size increases, what happens to its mass? What happens to its volume?

2. CHAPTER 2 Matter and change

3. Objectives  2.1a Explain why all samples of a substance have the same intensive properties.  2.1b Identify three states of matter.  2.1c Classify physical changes.  2.2a Explain how mixtures are classified and can be separated.  2.3a Explain the difference between an element and a compound.  2.3c Describe what chemists use to represent elements and compounds

4. Physical Properties  A physical property can be observed without changing the composition of the substance  Color  Hardness  Conductivity  Malleability  Melting Point  Boiling Point

5. Extensive properties  Mass and volume are considered extensive properties  they change depending on the amount of matter in a sample

6. Intensive properties  Intensive Properties, on the other hand, only depends on the type of matter in the sample, not the amount

7. Substances  A substance or pure substance is matter that has a uniform or definite composition

8. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved..  A solid is a form of matter that has a definite shape and volume.  The shape of a solid doesn’t depend on the shape of its container. States of Matter

9. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved..  A solid is a form of matter that has a definite shape and volume.  The shape of a solid doesn’t depend on the shape of its container. States of Matter The particles in a solid are packed tightly together, often in an orderly arrangement.

10. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved..  A solid is a form of matter that has a definite shape and volume.  As a result, solids are almost incompressible; that is, it is difficult to squeeze a solid into a smaller volume.  In addition, solids expand only slightly when heated. Solids States of Matter

11. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved..  The particles in a liquid are in close contact with one another, but the arrangement of particles in a liquid is not rigid or orderly. Liquids States of Matter

12. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved..  The particles in a liquid are in close contact with one another, but the arrangement of particles in a liquid is not rigid or orderly. Liquids States of Matter Because the particles in a liquid are free to flow, a liquid takes the shape of the container in which it is placed.

13. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved..  The particles in a liquid are in close contact with one another, but the arrangement of particles in a liquid is not rigid or orderly. Liquids States of Matter However, the volume of the liquid doesn’t change as its shape changes.

14. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved..  The volume of a liquid is fixed or constant.  Thus, a liquid is a form of matter that has an indefinite shape, flows, and yet has a fixed volume. Liquids States of Matter

15. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved..  The volume of a liquid is fixed or constant.  Thus, a liquid is a form of matter that has an indefinite shape, flows, and yet has a fixed volume. Liquids States of Matter – Liquids are almost incompressible. – However, they tend to expand slightly when heated.

16. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.. Like a liquid, a gas takes the shape of its container. But, unlike a liquid, a gas can expand to fill any volume. Gases States of Matter

17. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved..  A gas is a form of matter that takes both the shape and volume of its container. Gases States of Matter

18. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved..  A gas is a form of matter that takes both the shape and volume of its container. Gases States of Matter The particles in a gas are usually much farther apart than the particles in a liquid.

19. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved..  A gas is a form of matter that takes both the shape and volume of its container. Gases States of Matter The particles in a gas are usually much farther apart than the particles in a liquid. Because of the space between particles, gases are easily compressed into a smaller volume.

20. Mixtures  A mixture is a physical blend of two or more components

21. Heterogenous mixtures  A heterogenous mixture is a mixture in which the composition is not uniform throughout.  Salad dressing  Water and sand  Gravel

22. Homogenous mixture  A homogenous mixture is one where the composition is uniform throughout  Mixture is said to be in one phase, or part of the sample with uniform composition and properties

23. Separating mixtures  How might you separate:  Sand mixed with water?  Salt mixed with water?  Oil and vinegar?  Water and alcohol?

24. Separating mixtures  In a heterogenous mixture of a solid and a liquid, you can separate the components using filtration

25. Separating mixtures  Evaporation is used to separate solids that are dissolved in liquids  Separation is used to separate liquids that cannot mix  Tool: Separation Funnel

26. Separating mixtures  A liquid in a homogenous mixture can be separated through distillation.  Liquid is boiled to produce a vapor that is condensed into a liquid

27. HW: Open-ended Question (To be collected)  “Dry tea is a mixture, not a substance”  Write a paragraph in support of this statement.  How might you separate the components of dry tea leaves? How might you separate the components of a cup of tea?

28. Separating mixtures  How might you separate:  Sand mixed with water? Filtration  Salt mixed with water? Evaporation  Oil and vinegar? Separation  Water and alcohol? Distillation

29. Elements and compounds  An element is the simplest form of matter that has unique properties  A compound is a substance that contains one or more element that has been chemically combined. ElementCompound SodiumSodium ChlorideChlorine

30. Elements!

31. Homework  Read Sections 2.1-2.2 (p. 34-41)  P. 37, questions 1-5  P. 41, questions 12-16  P. 47, question 22  Read Lab Background and Procedure- Be ready to perform the lab!  Test: Planned for Wednesday. (Chapters 1 and 2)

32. Do-now: Answer the following  When you make a grilled cheese sandwich, what changes to the sandwich are permanent? What changes are temporary?

33. Objectives  2.3c Describe what chemists do not use to represent elements and compounds.  2.4a Describe what happens during a monopoly game.  2.4b Identify four possible clues that a chemical change has taken place.  2.4c Describe how the mass of reactants and the mass of products of a chemical reaction are related.

34. Symbols and Formulas  Every element can be represented by a one or two letter chemical symbol  “International language” for chemists  Chemical Formulas indicate compounds, and have more than one chemical symbol

35. Wanna hear a joke about Sodium, Bromine, and Oxygen? NaBrO

36. Want some Barium, Cobalt, and Nitrogen?

37. Sodium Batman?

39. Helium, Helium, Helium

40. The Periodic Table  The Periodic Table is an arrangement of elements in which the elements are separated into groups based on a set of repeating properties

41. The Periodic Table  Period- horizontal row of the periodic table  Group- vertical row of the periodic table

42. GROUPS on the Table

43. Visuals  Look on p. 46-47  Why do some elements have symbols similar to their names when others have symbols that have nothing to do with their names?  Are the elements in alphabetical order?  What do the numbers above the symbols represent?

44. Sample Problem  Identify each as an element, compound or mixture  Epsom Salt (magnesium sulfate)  Hydrogen Peroxide (H2O2)  Mercury (Hg)  Sweetened Iced tea

45. Physical Changes  During physical changes, the properties of a material change, but the composition of the material does not change  Boiling  Freezing  Melting  Condensing  Breaking  Splitting  Grinding  Cutting

46. We turn one material into a completely new material? But What if…

47. Chemical Changes  A chemical change is a change that produces matter with a different composition than the original matter

48. 2.4 Chemical Reactions  Chemical Property- the ability of a specific substance to undergo a chemical change  Different from physical property… how?

49. Reactants  Before a chemical change occurs, you need an initial substance  Reactant: substance present at the start of the reaction

50. Products  Products: Substance produced in the reaction Carbon Dioxide is the product of burning coal

51. Recognizing Chemical Changes  Four clues a chemical change has taken place 1. Transfer of energy 2. Change in color 3. Production of a gas 4. Formation of a Precipitate

52. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.. Recognizing Chemical Changes Clues to chemical change often have practical applications. Bubbles of carbon dioxide form when two antacid tablets are dropped into a glass of water. Production of a Gas

53. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.. Recognizing Chemical Changes Clues to chemical change often have practical applications. When a test strip is dipped in a solution, the color change is used to determine the pH of the solution. Color Change

54. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.. Recognizing Chemical Changes Clues to chemical change often have practical applications. One step in the production of cheese is a reaction that causes milk to separate into solid curds and liquid whey. Formation of a Precipitate

55. The law of conservation of mass  The law of conservation of mass states that in any physical change or chemical reaction, mass is conserved.  Mass cannot be created or destroyed  Holds true in chemical and physical changes!

56. Demo

58. Homework  Read Chapter 2.3 and 2.4 (p. 42-47)  Answer “Lesson Check” questions for 2.3 and 2.4.  TEST THURSDAY!

59. Do-now  Chemical or Physical Property?  Boiling point  Flammability  Color  Acidity  Chemical or Physical Change?  Rusting  Spoiling  Evaporating  Crushing