Understanding Matter: Properties and States

1. Chapter 3.1 Properties and States of Matter

2. Objectives Describe the two properties of all matter. Describe the difference between a pure substance and a mixture. Define physical properties. Define chemical properties. Explain how matter is organized. Chapter 3 Section 1 Properties of Matter

3. What is Matter? Matter has mass and takes up space. Everything you can see in the universe is matter. Atoms are the Building Blocks of Matter All matter is made from particles called atoms . Atom is the smallest unit of matter that has unique properties. Chapter 3 Section 1 Properties of Matter

4. Pure Substances A pure substance consists of one type of atom or one type of molecule. A pure substance may be an element or a compound . A molecule is not necessarily a compound. Chapter 3 Section 1 Properties of Matter

5. Pure Substances, continued Elements: A Single Type of Atom Elements cannot be broken down chemically or physically. An element is a single kind of atom. There are more than 100 different elements. Three Major Categories of Elements Metals Metalloids Non-metals Chapter 3 Section 1 Properties of Matter

6. Chapter 3 Section 1 Properties of Matter

7. Pure Substances, continued Molecules & Compounds A Molecule is two or more atoms joined by chemical bonds A molecule has a fixed composition all of its molecules have the same atoms in the same proportion. A compound is a molecule of two or more different atoms joined by chemical bonds. Chapter 3 Section 1 Properties of Matter

8. Chapter 3 Section 1 Properties of Matter

9. Mixtures A mixture contains two or more pure substances. A homogeneous mixture is uniform throughout, such as apple juice. A heterogeneous mixture is not uniformly mixed, such as salad dressing. A mixture can be separated with physical methods Chapter 3 Section 1 Properties of Matter

10. Mixtures, continued A Solution is a mixture that appears to be a single substance. The particles are too small to be affected by gravity and do not separate. Salt water Many solutions are liquids, but may also be a gas or solid. air Chapter 3 Section 1 Properties of Matter

11. Mixtures, continued Suspensions A mixture where the particles eventually settle out. May be gas or liquid. Colloids A mixture that has particles larger than a solution Particles do not settle out. May be solid, liquid, or gas. Chapter 3 Section 1 Properties of Matter

12. Identifying Matter with Physical Properties A physical property is a characteristic of a substance that can be observed or measured. Examples are mass, density, color, hardness, melting point, boiling point. Chapter 3 Section 1 Properties of Matter

13. Identifying Matter with Physical Properties, continued Mass and Weight The amount of matter in an object is called mass . Mass is constant at any place in the universe, because the amount of matter does not change. Chapter 3 Section 1 Properties of Matter

14. Identifying Matter with Physical Properties, continued Mass and Weight The force of gravity on an object is called weight . Weight is sometimes confused with mass. Weight varies depending on where you are in the universe. Weight on moon is 1/6 th of weight on earth Mass on moon is the same as on earth Chapter 3 Section 1 Properties of Matter

15. Section 1 Properties of Matter Chapter 3 Comparing Mass and Weight

16. Identifying Matter with Physical Properties, continued Volume The amount of space matter occupies is called volume . Density The mass of an object per unit of volume is called its density. Density is found by dividing mass by volume. Chapter 3 Section 1 Properties of Matter

17. Identifying Matter with Physical Properties, continued Other Important Physical Properties can help identify and classify matter. Malleability substances are soft, such as aluminum how well it can be shaped. Conductivity - how well a substance conducts electricity. boiling point . Chapter 3 Section 1 Properties of Matter

18. Identifying Matter with Chemical Properties Chemical Properties describe matter based on its ability to participate in chemical reactions and form new substances. Reactivity is the ability of substances to combine and form one or more new substances. Chapter 3 Section 1 Properties of Matter

19. Categories of Matter and Their Properties Classification based on the chemical and physical properties of matter. Properties of Pure Substances All pure substances have the same composition, and exactly the same physical and chemical properties. Chapter 3 Section 1 Properties of Matter

20. Categories of Matter and Their Properties, continued Pure substances are either elements or compounds. Elements are composed of the same atoms . Compounds are composed of the same molecules . Chapter 3 Section 1 Properties of Matter

21. Categories of Matter and Their Properties, continued Properties of Mixtures The physical and chemical properties of a mixture can vary. A mixture is a blend of pure substances which retain their identity and properties. All matter can be classified according to the categories shown on the next slide. Chapter 3 Section 1 Properties of Matter

22. Section 1 Properties of Matter Chapter 3

23. Section 2 Objectives Define the law of conservation of mass . Describe the difference between physical and chemical changes. Explain why some changes are reversible and some are not. Chapter 3 Section 2 Physical and Chemical Changes

24. Conservation of Mass Mass is not created or destroyed in ordinary chemical or physical changes. In ordinary physical or chemical changes, the amount of matter, which is called mass , does not change. Chapter 3 Section 2 Physical and Chemical Changes

25. Conservation of Mass Lab 1. Weigh a clean, dry cup: _________ 2. Add a small amount of vinegar and re-weigh: ____ 3. Amount of Vinegar = (#2 - #1) = ______________ 4. Weigh a 2 nd clean, dry cup:_________ 5. Add a small amount of baking soda and re- weigh:_______ 6. Amount of Baking soda = (#5 - #4) = __________ 7. Total Mass of reactants: (#6 + #3) = __________ 8. SLOWLY add the baking soda to the vinegar. If it overflows, you have to start over. 9. Weigh the resulting mixture and cup: _______ 10. Total Mass of Products (#9 - #1)= ___________ 11. Was Conservation of Mass upheld? Does #10 = #7? Explain why or why not.

26. Physical Changes in Our World A physical change is any change in which the properties of a substance, but not the identity of the substance, change. The next slide shows the physical changes that occur when sulfur and salt are separated. Chapter 3 Section 2 Physical and Chemical Changes

27. Chapter 3 Section 2 Physical and Chemical Changes

28. Physical Changes in Our World, continued Physical Changes in Nature Movement of soil and rock Ponds freezing Water freezing or melting Physical Changes in Industry Making sugar Building furniture Chapter 3 Section 2 Physical and Chemical Changes

29. Chemical Change in Our World A chemical change occurs when new substances are formed Different identity Different physical properties. A Chemical Change producing new substances are also called chemical reactions . Chapter 3 Section 2 Physical and Chemical Changes

30. Chemical Change in Our World, continued Chemical Changes in Nature Photosynthesis Digestion. Physical Changes in Industry Making metal Refining oil for gasoline. Chapter 3 Section 2 Physical and Chemical Changes

31. Are Physical and Chemical Changes Reversible? Most physical changes are reversible Physical changes only affect the matters form. Most chemical changes are not reversible. Chapter 3 Section 2 Physical and Chemical Changes

32. Section 3 Objectives Explain why particles in matter are always in motion. Compare the properties of solids, liquids, and gases. Explain the behavior of gases. Describe plasma. Chapter 3 Section 3 States of Matter

33. Particles of Matter in Motion There are movements in matter that are too small to see or feel. Particles in matter are always in motion because particles have energy. Chapter 3 Section 3 States of Matter

34. Particles of Matter in Motion, continued States of Matter Determined by Particle Energy The more energy a particle has, the faster it moves. Particle energy and movement determines the physical forms of matter, or the states of matter . Four states of matter are solid , liquid , gas , and plasma . They are physically different because their particles have different amounts of energy. Chapter 3 Section 3 States of Matter

35. Chapter 3 Section 3 States of Matter

36. Physical Differences Between States of Matter Solids Have Rigid Structure Particles are fixed into place water molecules in ice. Does not change shape or size. Temperature measures the energy of the particles. The temperature at which a solid change to liquid is called its melting point . Chapter 3 Section 3 States of Matter

37. Physical Differences Between States of Matter, continued Liquids A liquid assumes the shape of its container. Molecules are in contact with each other, but are not held rigidly in place. A liquid has a definite volume but no definite shape. Chapter 3 Section 3 States of Matter

38. Physical Differences Between States of Matter, continued Gas The particles of matter have enough energy to escape their attraction to each other. Due to their high energy and rapid motion, particles of a gas fill whatever volume is available. A gas has no definite shape and no definite volume. Chapter 3 Section 3 States of Matter

39. Physical Differences Between States of Matter, continued Changing from One State to Another Changes occur when energy is added to or removed from a substance. The change from a liquid to a gas is called evaporation or boiling . Energy is added to the liquid to cause its molecules to escape the attraction to one another. Chapter 3 Section 3 States of Matter

40. Physical Differences Between States of Matter, continued When a gas is cooled, attractions between the particles becomes stronger and the gas condenses into a liquid . When a liquid changes to a solid, it freezes . The liquid cools enough for attractions between the particles to lock the particles into fixed positions. Chapter 3 Section 3 States of Matter

41. Section 3 States of Matter Chapter 3 Solid, Liquid and Gas

42. Behavior of Gases The volume of a gas is the amount of space taken up by the gas particles in a container. Temperature Heat causes a gas to expand because the molecules have more energy. Cold causes the gas to contract because the molecules move slower. Chapter 3 Section 3 States of Matter

43. Behavior of Gases, continued Volume The volume of a gas depends on the container that holds the gas. Pressure measures the amount of force exerted per unit area of a surface. When air particles collide within a container, they exert more pressure. In the next slide, the beach ball has less pressure because it has fewer gas particles. Chapter 3 Section 3 States of Matter

44. Chapter 3 Section 3 States of Matter

45. Plasma: A Fourth State of Matter Plasma is a state of matter that starts as a gas and then becomes ionized. Its properties differ from those of a solid, liquid, or gas. Plasma is created when energy is added to a gas. Plasma is similar to a gas in that it has no fixed shape, but it is different in that it conducts electric current and is attracted to magnetic fields. Chapter 3 Section 3 States of Matter

46. Concept Mapping Chapter 3 Properties and States of Matter Use the terms below to complete the concept map on the next slide. changes of state melting evaporating solid liquid condensing chemical formulas

47. Chapter 3 Properties and States of Matter

48. Chapter 3 Properties and States of Matter

49. End of Chapter 3 Show Copyright by Holt, Rinehart and Winston. All rights reserved. Resources Chapter menu