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2. Matter—Properties and Change Section 3.1Properties of Matter Section 3.2Changes in Matter Section 3.3Mixtures of Matter Section 3.4Elements and Compounds Click a hyperlink or folder tab to view the corresponding slides. Exit Chapter Menu

3. Section 3.1 Properties of Matter • Identify the characteristics of a substance. • Distinguish between physical and chemical properties. • Differentiate among the physical states of matter. density: a ratio that compares the mass of an object to its volume Section 3-1

4. Section 3.1 Properties of Matter (cont.) states of matter solid liquid gas vapor physical property extensive property intensive property chemical property Most common substances exist as solids, liquids, and gases, which have diverse physical and chemical properties. Section 3-1

5. Substances • Matter is anything that has mass and takes up space. • Matter is everything around us. • Matter with a uniform and unchanging composition is a substance. Section 3-1

6. States of Matter • The physical forms of matter, either solid, liquid, or gas, are called the states of matter. • Solidsare a form of matter that have their own definite shape and volume. • Liquidsare a form of matter that have a definite volume but take the shape of the container. Section 3-1

7. States of Matter (cont.) • Gaseshave no definite shape or volume. They expand to fill their container. • Vaporrefers to the gaseous state of a substance that is a solid or liquid at room temperature. Section 3-1

8. Physical Properties of Matter • A physical propertyis a characteristic that can be observed or measured without changing the sample’s composition. Section 3-1

9. Physical Properties of Matter (cont.) • Extensive propertiesare dependent on the amount of substance present, such as mass, length, or volume. • Intensive propertiesare independent of the amount of substance present, such as density. Section 3-1

10. Chemical Properties of Matter • The ability of a substance to combine with or change into one or more other substances is called a chemical property. • Iron forming rust • Copper turning green in the air Section 3-1

11. Observing Properties of Matter • A substance can change form–an important concept in chemistry. • Chemical properties can change with specific environmental conditions, such as temperature and pressure. Section 3-1

12. A B C D Section 3.1 Assessment Density is what kind of property? A.atomic B.intensive C.extensive D.dependent Section 3-1

13. A B C D Section 3.1 Assessment What defines a gas? A.Gases have a definite volume and shape. B.Gases have a definite volume but take the shape of their container. C.Gases have no definite volume or shape. D.Gases have a definite shape but no definite volume. Section 3-1

14. End of Section 3-1

15. Section 3.2 Changes in Matter • Define physical change and list several common physical changes. • Define chemical change and list several indications that a chemical change has taken place. • Apply the law of conservation of mass to chemical reactions. observation: orderly, direct information gathering about a phenomenon Section 3-2

16. Section 3.2 Changes in Matter (cont.) physical change phase change chemical change law of conservation of mass Matter can undergo physical and chemical changes. Section 3-2

17. Physical Changes • A change that alters a substance without changing its composition is known as a physical change. • A phase changeis a transition of matter from one state to another. • Boiling, freezing, melting, and condensing all describe phase changes in chemistry. Section 3-2

18. Chemical Changes • A change that involves one or more substances turning into new substances is called a chemical change. • Decomposing, rusting, exploding, burning, or oxidizing are all terms that describe chemical changes. Section 3-2

19. Conservation of Mass • The law of conservation of massstates that mass is neither created nor destroyed in a chemical reaction, it is conserved. • The mass of the reactants equals the mass of the products. • massreactants = massproducts Section 3-2

20. A B C D Section 3.2 Assessment When one substances turns into another, what kind of change has taken place? A.chemical reaction B.physical reaction C.extensive reaction D.nuclear reaction Section 3-2

21. A B C D Section 3.2 Assessment The law of conservation of mass states that: A.Matter can be created and destroyed. B.Matter can be created but not destroyed. C.The products of a reaction always have a greater mass than the reactants. D.The products of a reaction must have the same mass as the reactants. Section 3-2

22. End of Section 3-2

23. Section 3.3 Mixtures of Matter • Contrast mixtures and substances. • Classify mixtures as homogeneous or heterogeneous. • List and describe several techniques used to separate mixtures. substance: a form of matter that has a uniform and unchanging composition; also known as a pure substance Section 3-3

24. Section 3.3 Mixtures of Matter (cont.) mixture heterogeneous mixture homogeneous mixture solution filtration distillation crystallization sublimation chromatography Most everyday matter occurs as mixtures—combinations of two or more substances. Section 3-3

25. Mixtures • A mixtureis a combination of two or more pure substances in which each pure substance retains its individual chemical properties. • A homogenous mixture is a mixture where the composition is constant throughout. Section 3-3

26. Mixtures (cont.) • Homogeneous mixtures are also called solutions. • A heterogeneous mixture is a mixture where the individual substances remain distinct. Section 3-3

27. Mixtures (cont.) Section 3-3

28. Separating Mixtures • Filtrationis a technique that uses a porous barrier to separate a solid from a liquid in a heterogeneous mixture. • Distillationis a separation technique for homogeneous mixtures that is based on the differences in boiling points of substances. • Crystallizationis a separation technique for homogenous mixtures that results in the formation of pure solid particles from a solution containing the dissolved substance. Section 3-3

29. Separating Mixtures (cont.) • Sublimationis the process of a solid changing directly to a gas, which can be used to separate mixtures of solids when one sublimates and the other does not. • Chromatographyis a technique that separates the components of a mixture on the basis of tendency of each to travel across the surface of another material. Section 3-3

30. A B C D Section 3.3 Assessment Which is NOT a technique for separating a homogenous mixture? A.crystallization B.distillation C.filtration D.chromatography Section 3-3

31. A B C D Section 3.3 Assessment Which of the following is a heterogeneous mixture? A.seawater B.silver mercury amalgam C.atmosphere D.salad dressing Section 3-3

32. End of Section 3-3

33. Section 3.4 Elements and Compounds • Distinguish between elements and compounds. • Describe the organization of elements in the periodic table. • Explain how all compounds obey the laws of definite and multiple proportions. proportion: the relation of one part to another or to the whole with respect to quantity Section 3-4

34. Section 3.4 Elements and Compounds (cont.) element periodic table compound law of definite proportions percent by mass law of multiple proportions A compound is a combination of two or more elements. Section 3-4

35. Elements • An elementis a pure substance that cannot be separated into simpler substances by physical or chemical means. • 92 elements occur naturally on Earth. • Each element has a unique name and a one, two, or three-letter symbol. • The periodic tableorganizes the elements into a grid of horizontal rows called periods and vertical columns called groups. Section 3-4

36. Compounds • A compound is a made up of two or more elements combined chemically. • Most of the matter in the universe exists as compounds. • Table salt, NaCl, and water, H2O, are compounds. Section 3-4

37. Compounds (cont.) • Elements can never be separated. • Compounds can be broken into components by chemical means. Section 3-4

38. Compounds (cont.) • This figure shows electrolysis of water to form hydrogen and oxygen. Section 3-4

39. Compounds (cont.) • The properties of a compound are different from its component elements. Section 3-4

40. Law of Definite Proportions • The law of definite proportionsstates that a compound is always composed of the same elements in the same proportion by mass, no matter how large or small the sample. Section 3-4

41. Law of Definite Proportions (cont.) • The relative amounts are expressed as percent by mass, the ratio of the mass of each element to the total mass of the compound expressed as a percentage. Section 3-4

42. Law of Definite Proportions (cont.) • This table demonstrates that the percentages of elements in sucrose remain the same despite differences in sample amount. Section 3-4

43. Law of Multiple Proportions • The law of multiple proportions states that when different compounds are formed by a combination of the same elements, different masses of one element combine with the same relative mass of the other element in whole number ratios. • H2O2 and H2O • Copper(I) chloride and copper(II) chloride Section 3-4

44. Law of Multiple Proportions (cont.) Section 3-4

45. A B C D Section 3.4 Assessment What is a period on the periodic table of the elements? A.a vertical columns B.even numbered elements only C.horizontal rows D.the last vertical column only Section 3-4

46. A B C D Section 3.4 Assessment An element is a substance that cannot be A.divided into simpler substances. B.combined to form a mixture. C.combined to form an element. D.different phases. Section 3-4

47. End of Section 3-4

48. Chemistry Online Study Guide Chapter Assessment Standardized Test Practice Image Bank Concepts in Motion Resources Menu

49. Section 3.1 Properties of Matter Key Concepts • The three common states of matter are solid, liquid, and gas. • Physical properties can be observed without altering a substance’s composition. • Chemical properties describe a substance’s ability to combine with or change into one or more new substances. • External conditions can affect both physical and chemical properties. Study Guide 1

50. Section 3.2 Changes in Matter Key Concepts • A physical change alters the physical properties of a substance without changing its composition. • A chemical change, also known as a chemical reaction, involves a change in a substance’s composition. • In a chemical reaction, reactants form products. • The law of conservation of mass states that mass is neither created nor destroyed during a chemical reaction; it is conserved. • massreactants = massproducts Study Guide 2