2. Ch 2 Matter

3. Ch 1 Matter Chapter 2 Table of Contents Section 1 What is Matter? Section 2 Properties of Matter Section 3 Changes of Matter

4. Section 1 What Is Matter? Section 1 Objectives Explain the relationship between matter, atoms, and elements. Explain the relationship between matter, atoms, and elements. Distinguish between elements and compounds. Distinguish between elements and compounds. Describe molecules, and explain how they are formed. Describe molecules, and explain how they are formed. Interpret and write some common chemical formulas. Interpret and write some common chemical formulas. Categorize materials as pure substances or mixtures. Categorize materials as pure substances or mixtures. Chapter 2

5. Composition of Matter Atoms are matter. Atoms are matter. Everything in the universe is made up of matter.Everything in the universe is made up of matter. Matter is anything that has mass and takes up space. Matter is anything that has mass and takes up space. Chemistry is the scientific study of the composition, structure, and properties of matter and the changes that matter undergoes. Chemistry is the scientific study of the composition, structure, and properties of matter and the changes that matter undergoes. Section 1 What Is Matter? Chapter 2

6. Element a substance that cannot be separated or broken down into simpler substances by chemical means. Element a substance that cannot be separated or broken down into simpler substances by chemical means. Atom the smallest unit of an element that maintains the properties of that element. Atom the smallest unit of an element that maintains the properties of that element.

7. Elements in the Human Body Section 1 What Is Matter? Chapter 2

8. Composition of Matter Compound a substance made of atoms of two or more different elements that are chemically combined. Compound a substance made of atoms of two or more different elements that are chemically combined. Ex- H 2 O- water Ex- H 2 O- water Section 1 What Is Matter? Chapter 2

10. Composition of Matter Compounds have unique properties. Compounds have unique properties. Every compound is different from the elements it contains. **Na Demo Every compound is different from the elements it contains. **Na DemoEx- Na-?????? Sodium- Soft highly reactive metal Cl- ????? Chlorine- yellow poisonous gas. NaCl- ????? Table salt- white “ salty ” substance Section 1 What Is Matter? Chapter 2

11. Composition of Matter Atoms can join together to make millions of molecules. Molecules are the smallest unit of a substance that keeps all of the physical and chemical properties of that substance. Video- Matter 20 min Video- Matter 20 min Section 1 What Is Matter? Chapter 2

12. Molecule Section 1 What Is Matter? Chapter 2 Molecules are 2 or more atoms bonded together. Atoms can be the same or different. Ex- O 2 - oxygen molecule CO 2 - Carbon dioxide H 2 0

13. Composition of Matter Chemical formula a combination of chemical symbols and numbers that represent a substance. Ex- NaCl- salt Ex- NaCl- salt H 2 O- water H 2 O- water A chemical formula shows how many atoms of each element are in a unit of a substance. A chemical formula shows how many atoms of each element are in a unit of a substance. Section 1 What Is Matter? Chapter 2

14. Mixtures Mixture a combination of two or more substances that are not chemically combined. Mixture a combination of two or more substances that are not chemically combined. Retain’s original properties. Retain’s original properties. Formed by mixing pure substances. Formed by mixing pure substances. Ex- Salt in water. Still salty & can be seperated. Ex- Salt in water. Still salty & can be seperated. Kool aid- still sweet- no chemical changes. Kool aid- still sweet- no chemical changes. Section 1 What Is Matter? Chapter 2

16. Pure Substances and Mixtures Mixtures are classified by how thoroughly the substances mix. Heterogeneous mixture substances aren’t mixed uniformly and are not evenly distributed. Ex- Mixture of candy Heterogeneous mixture substances aren’t mixed uniformly and are not evenly distributed. Ex- Mixture of candy Homogeneous mixture substances are evenly distributed, and the mixture is the same throughout. 1 dissolves in the other Homogeneous mixture substances are evenly distributed, and the mixture is the same throughout. 1 dissolves in the other Ex- Kool aid Ex- Kool aid Video mixture 1min Video mixture 1min Video mixture 1min Video mixture 1min Video- hetero & homogenous mix Video- hetero & homogenous mix Video- hetero & homogenous mix Video- hetero & homogenous mix Section 1 What Is Matter? Chapter 2

17. Miscible substances that can be mixed Miscible substances that can be mixed Ex- sugar in water- dissolves Ex- sugar in water- dissolves Immiscible substances that cannot be mixed Immiscible substances that cannot be mixed Ex –Water & oil Ex –Water & oil

18. Pure Substances and Mixtures Gases can mix with liquids. Gases can mix with liquids. Air is a mixture of gases.Air is a mixture of gases. Examples of gases mixed with liquids includeExamples of gases mixed with liquids include carbonated drinkscarbonated drinks oxygen dissolved in wateroxygen dissolved in water foamfoam Section 1 What Is Matter? Chapter 2

19. Objectives Distinguish between the physical and chemical properties of matter, and give examples of each. Distinguish between the physical and chemical properties of matter, and give examples of each. Perform calculations involving density. Perform calculations involving density. Explain how materials are suited for different uses based on their physical and chemical properties, and give examples. Explain how materials are suited for different uses based on their physical and chemical properties, and give examples. Describe characteristic properties, and give examples. Describe characteristic properties, and give examples. Section 2 Properties of Matter Chapter 2

20. Bellwork You are already familiar with the most common states of matter: solid, liquid, and gas. For example you can see solid ice and liquid water. You cannot see water vapor, but you can feel it in the air on a humid summer day. How do you think the atoms and molecules are arranged in these different states? Examine the drawings shown below. Then answer the items that follow. Section 2 Properties of Matter Chapter 2

21. Bell work 1. Think about the properties of ice. It is somewhat hard and cannot be compressed easily. Which drawing do you think cannot be compressed easily. Which drawing do you think represents a solid? Why? represents a solid? Why? 2. Think about the properties of gases. They are not hard, and they can be compressed. they can be compressed. Which drawing represents a gas? Why? Which drawing represents a gas? Why? 3. In which state(s) of matter are the particles touching? 4. In which drawing do you think the particles have the least effect on one another? Why? effect on one another? Why? Section 2 Properties of Matter Chapter 2

22. Physical Properties Physical properties describe matter. Physical properties describe matter. Some physical properties of matter include shape, color, size, mass, volume, density, odor, melting point and boiling point. Some physical properties of matter include shape, color, size, mass, volume, density, odor, melting point and boiling point. Section 2 Properties of Matter Chapter 2

23. Physical properties Melting point the temperature and pressure at which a solid becomes a liquid. Melting point the temperature and pressure at which a solid becomes a liquid. Boiling point the temperature and pressure at which a liquid becomes a gas. Boiling point the temperature and pressure at which a liquid becomes a gas. State the physical form in which a substance exists, such as solid, liquid, or gas. State the physical form in which a substance exists, such as solid, liquid, or gas.

24. Three States of Water Section 2 Properties of Matter Chapter 2

25. Physical Properties Density is a physical property. Density is a physical property. Density is a measurement of how much matter is contained in a certain volume of a substance.Density is a measurement of how much matter is contained in a certain volume of a substance. Section 2 Properties of Matter Chapter 2 List of elements by density

26. Physical Properties The equation for density is D = M/V Density = mass/volumeDensity = mass/volume The density of a liquid or solid is usually reported in units of grams per cubic centimeter (g/cm 3 ) or (g/ml).The density of a liquid or solid is usually reported in units of grams per cubic centimeter (g/cm 3 ) or (g/ml). Section 2 Properties of Matter Chapter 2

27. Volume= M/D Volume= M/D M M Mass= V x D Mass= V x D Video- Density 3min D V Video- Density 3min D V Video- Density 3min Video- Density 3min

28. Math Skills Density If 10.0 cm 3 of ice has a mass of 9.17 g, what is the density of ice? 1. List the given and unknown values. Given: mass, m = 9.17 g volume, V = 10.0 cm 3 Unknown: density, D = ? g/cm 3 Section 2 Properties of Matter Chapter 2

29. Math Skills 2. Write the equation for density. density = m/v 3. Insert the known values into the equation, and solve. D = 9.17 g/10.0 cm 3 Section 2 Properties of Matter Chapter 2 D = 0.917 g/cm 3

30. Physical Properties Physical properties are used to select substances that may be useful. Physical properties are used to select substances that may be useful. Examples of useful physical properties include:Examples of useful physical properties include: low freezing point ex- antifreezelow freezing point ex- antifreeze high boiling point ex- antifreeze- cooling car enginehigh boiling point ex- antifreeze- cooling car engine water resistance ex- water proofing materialswater resistance ex- water proofing materials flexibilityflexibility electrical conductorsex- wiringelectrical conductorsex- wiring heat conductorsex- cookingheat conductorsex- cooking Section 2 Properties of Matter Chapter 2

31. Chemical Properties Chemical properties describe how a substance reacts. Chemical properties describe how a substance reacts. Chemical properties describe how a substance changes into a new substance when in contact with other elements. Chemical properties describe how a substance changes into a new substance when in contact with other elements.

32. Chemical Properties Reactivity the ability of a substance to combine chemically(bond) with another substance. Reactivity the ability of a substance to combine chemically(bond) with another substance. Flammability the ability of a substance to react in the presence of oxygen and burn when exposed to a flame. Flammability the ability of a substance to react in the presence of oxygen and burn when exposed to a flame. Section 2 Properties of Matter Chapter 2

33. Reactivity Video chemical properties 1min Video chemical properties 1min Video chemical properties 1min Section 2 Properties of Matter Chapter 2

34. Comparing Physical and Chemical Properties Characteristic properties help to identify and classify substances. Characteristic properties help to identify and classify substances. The table below compares some physical and chemical properties.The table below compares some physical and chemical properties. Section 2 Properties of Matter Chapter 2

35. Bellringer Physical properties are characteristics of a substance that can be observed without changing the composition of the substance. Physical properties are often used to separate a mixture into its original components. Imagine that you have been given a mixture of sand, sugar, and iron filings. You know that iron is attracted to a magnet, sugar dissolves in water and sand does not, and sugar has a higher boiling point than water. Each of these properties is a physical property. Think about how you can use these facts about the physical properties of the sand, sugar, and iron filings in order to separate them out of the mixture. Section 3 Changes of Matter Chapter 2

36. Bellringer 1. What do you separate in the first step? How? 2. What is separated out in the second step? How? 3. What happens in the third step? Section 3 Changes of Matter Chapter 2

37. Section 3 Changes of Matter Objectives Explain physical change, and give examples of physical change. Explain physical change, and give examples of physical change. Explain chemical change, and give examples of chemical changes. Explain chemical change, and give examples of chemical changes. Compare and contrast physical and chemical changes. Compare and contrast physical and chemical changes. Describe how to detect whether a chemical change has occurred. Describe how to detect whether a chemical change has occurred. Chapter 2

38. Physical Changes Physical changes do not change a substance ’ s identity. Physical changes do not change a substance ’ s identity. Physical change a change of matter from one form to another without a change in chemical properties. Physical change a change of matter from one form to another without a change in chemical properties. Video- Physical change 6.43 min Video- Physical change 6.43 min Video- Physical change 6.43 min Video- Physical change 6.43 min Section 3 Changes of Matter Chapter 2

39. Physical Changes Dissolving is a physical change. Dissolving is a physical change. When a substance dissolves, the molecules of the substance do not change.When a substance dissolves, the molecules of the substance do not change. Dissolving a solid in a liquid, a gas in a liquid, or a liquid in a liquid are all physical changes.Dissolving a solid in a liquid, a gas in a liquid, or a liquid in a liquid are all physical changes. Section 3 Changes of Matter Chapter 2

40. Physical Changes Mixtures can be physically separated. Mixtures can be physically separated. Because mixtures are not chemically combined, each component of the mixture has the same chemical makeup it had before the mixture was formed.Because mixtures are not chemically combined, each component of the mixture has the same chemical makeup it had before the mixture was formed. Mixtures can be separated based on their physical properties.Mixtures can be separated based on their physical properties. Section 3 Changes of Matter Chapter 2

41. Separating Mixtures Section 3 Changes of Matter Chapter 2

42. Chemical Changes Chemical change a change that occurs when a substance changes composition by forming one or more new substances. Chemical change a change that occurs when a substance changes composition by forming one or more new substances. Examples of chemical changes include:Examples of chemical changes include: burningburning rustingrusting digestingdigesting decomposingdecomposing Section 3 Changes of Matter Chapter 2

43. Chemical Changes Chemical changes form new substances that have different properties. Chemical changes form new substances that have different properties. The results of a chemical change are substances that have completely different properties from the properties of the original substances.The results of a chemical change are substances that have completely different properties from the properties of the original substances. Section 3 Changes of Matter Chapter 2

44. Chemical Changes Section 3 Changes of Matter Chapter 2

45. Chemical Changes Chemical changes can be detected. Chemical changes can be detected. Changes in physical properties can be an indication of a chemical change.Changes in physical properties can be an indication of a chemical change. Examples include:Examples include: change of colorchange of color change of smellchange of smell Fizzing(gasses produced)Fizzing(gasses produced) production of heat/coldproduction of heat/cold production of soundproduction of sound production of lightproduction of light Section 3 Changes of Matter Chapter 2

46. Chemical Changes Chemical changes cannot be reversed by physical changes. Chemical changes cannot be reversed by physical changes. Because new substances are formed in a chemical change, the change cannot be reversed by using physical changes.Because new substances are formed in a chemical change, the change cannot be reversed by using physical changes. Many chemical changes are impossible to reverse, for example it is impossible to “ unbake ” a cake.Many chemical changes are impossible to reverse, for example it is impossible to “ unbake ” a cake. Video- chemical change 6minVideo- chemical change 6minVideo- chemical change 6minVideo- chemical change 6min Section 3 Changes of Matter Chapter 2

47. Chemical Changes Compounds can be broken down through chemical changes. Compounds can be broken down through chemical changes. Some compounds undergo chemical changes to form elements, others break down to form simpler substances.Some compounds undergo chemical changes to form elements, others break down to form simpler substances. Section 3 Changes of Matter Chapter 2

48. Concept Mapping Section 3 Changes of Matter Chapter 2

49. Understanding Concepts 1. Which of the following substance is a compound? A.air B.carbon dioxide C.nitrogen D.oxygen Standardized Test Prep Chapter 2

50. Understanding Concepts, continued 1. Which of the following substance is a compound? A.air B.carbon dioxide C.nitrogen D.oxygen Standardized Test Prep Chapter 2

51. Understanding Concepts, 2. If vinegar is poured into two test tubes containing white powders that look identical, which of the following statements is a reasonable conclusion as to why bubbles form in one tube but not the other? F.The test tubes contain two different mixtures. G.The contents of the test tubes are two different pure substances. H.The materials in the two test tubes cannot be the same substance. J.One test tube contains an element, and the other contains a compound. Standardized Test Prep Chapter 2

52. Understanding Concepts 2. If vinegar is poured into two test tubes containing white powders that look identical, which of the following statements is a reasonable conclusion as to why bubbles form in one tube but not the other? F.The test tubes contain two different mixtures. G.The contents of the test tubes are two different pure substances. H.The materials in the two test tubes cannot be the same substance. J.One test tube contains an element, and the other contains a compound. Standardized Test Prep Chapter 2

53. Understanding Concepts, 3. Which of these is a physical change? A.the combustion of gasoline in an engine B.the expansion of air in a balloon when it is heated C.the conversion of milk to yogurt by microorganisms D.the change in color of a bronze statue from copper to green Standardized Test Prep Chapter 2

54. Understanding Concepts, 3. Which of these is a physical change? A.the combustion of gasoline in an engine B.the expansion of air in a balloon when it is heated C.the conversion of milk to yogurt by microorganisms D.the change in color of a bronze statue from copper to green Standardized Test Prep Chapter 2

55. Understanding Concepts, continued 4. Iron, gold, copper, and silver are all elements that are metals. Based on these elements, what are some of the physical properties that could be used to classify a substance as a metal?. Standardized Test Prep Chapter 2

56. Understanding Concepts, 4. Iron, gold, copper, and silver are all elements that are metals. Based on these elements, what are some of the physical properties that could be used to classify a substance as a metal? Answer: Metals are dense, shiny, hard, solid at room temperature. In wires or sheets, they can be bent without breaking. Standardized Test Prep Chapter 2

57. Understanding Concepts, continued 5. How could an engineer use the physical properties of water and dissolved salts to develop a system for producing drinking water from seawater? Standardized Test Prep Chapter 2

58. Understanding Concepts, 5. How could an engineer use the physical properties of water and dissolved salts to develop a system for producing drinking water from seawater? Answer: Water is a covalent compound that boils at a lower temperature than the ionic dissolved salts. The saltwater can be heated until the water becomes a gas. When the gas condenses, the water no longer has dissolved salts. Standardized Test Prep Chapter 2

59. Reading Skills Most of the elements were originally discovered on Earth, but helium was first found in the sun. Every element emits light at specific wavelengths when it is heated. The first evidence that helium existed was a line in the spectrum of the sun that did not match any produced by known elements. The astronomer who discovered helium was examining a spectrum of sunlight taken during an eclipse, when only the outer part of the sun is visible. Helium was not isolated from Earth’s atmosphere until more than 20 years after its discovery. 6. How could scientists know that helium was a different element from any previously discovered, without having isolated any helium on Earth? Standardized Test Prep Chapter 2

60. Reading Skills, continued 6. [See previous slide for question.] Answer: Each element is different and has specific properties. These properties are the same no matter whether the element is on Earth or the sun. Standardized Test Prep Chapter 2

61. Interpreting Graphics 7. Examine the illustration of sugar molecules in water. Why is it that sugar does not dissolve immediately when it is placed in water? Standardized Test Prep Chapter 2

62. Interpreting Graphics, continued 7. [See previous slide for question and illustration.] A sugar molecule does not dissolve in water until it is completely surrounded by water molecules. The interior molecules in a crystal can’t dissolve until those on the outside have been removed. A sugar molecule does not dissolve in water until it is completely surrounded by water molecules. The interior molecules in a crystal can’t dissolve until those on the outside have been removed. Standardized Test Prep Chapter 2