MATTER

1. MATTER CHAPTER 2 The Nature of Matter

2. Objectives Explain the relationships between matter, atoms, and elements. Distinguish between elements and compounds. Interpret and write some common chemical formulas. Categorize materials as pure substance or mixture.

3. Vocabulary Chemistry Matter Element Atom Compound Molecule Chemical Formula Pure Substance Mixture Miscible immiscible

4. 2.1 WHAT IS CHEMISTRY? MATTER HOW IT CHANGES Chemistry is the study of matter and how it changes. Make list of some things that are matter and another list of how it may change.

5. 2.1 WHAT IS MATTER? MATTER IS ANYTHING THAT HAS mass AND OCCUPIES space. Make a list of things that are matter and things that are not matter. MATTER NOT MATTER 1. 1. 2. 2. 3. 3.

6. ELEMENTS � contain only one kind of ATOM. For example: Iron Fe, Zinc Zn, Aluminum Al The smallest part of an element is an ATOM. COMPOUNDS � contain atoms of more than one kind of element. For example: Benzene C6H6 The smallest part of a compound is a MOLECULE . ELEMENT is to ATOM as COMPOUND is to MOLECULE!!

7. Compounds Two or more elements combine chemically to make a compound. Every compound is unique and is different from the elements it contains. When elements combine to make a specific compound, the elements always combine in the same proportions.

8. Molecules Atoms can join together to make millions of different molecules, just as letters of the alphabet combine to form different words. When atoms combine they act like an unit. That is what a molecule is�the smallest unit of a substance that behaves like the substance.

10. Definitions Element: a substance that cannot be broken down into simpler substances. Atom: The smallest particle that has the properties of an element. Compound: A substance made of atoms or more than one element bound together. Molecule: the smallest unit of a substance that exhibits all the properties characteristic of that substance.

11. Chemical Formulas Represent Compounds and Molecules Chemical Formula: the chemical symbols and numbers indicating the atoms contained in the basic unit of a substance. Example: The sugar molecule glucose has six carbon atoms, twelve hydrogen atoms and six oxygen atoms, so its chemical formula is C6H12O6 This chemical formula shows that it is made of three elements and 24 atoms

12. PURE SUBSTANCE or MIXTURE? PURE SUBSTANCE fixed composition definite properties all the elements (listed on the periodic table) all compounds (all have a formula) Examples: distilled water, salt� MIXTURE a combination of more than one pure substance. can be separated into pure substances proportions may vary Examples: most water, air �

13. Notes Pure substances blended together make mixtures. While a compound is different from the elements that make it, a mixture may have some properties similar to the pure substances that make it. Mixtures are classified by how thoroughly the substances mix. Gases can mix with liquids

14. Notes Heterogeneous mixtures are substances that are not uniformly mixed. Homogeneous mixtures occurs between the individual units and is the same throughout.

15. TYPES OF MIXTURES: HETEROGENEOUS or not uniformly mixed after time the substances may settle liquids are immiscible Fresh milk from a cow Orange juice with pulp HOMOGENEOUS uniformly mixed can not easily be separated liquids are miscible Store milk that has been homogenized soda

16. MIXTURES MAY BE ANY COMBINATION OF SOLIDS, LIQUIDS OR GASES. SOLID/SOLID - _________________ SOLID/LIQUID - ________________ SOLID/GAS - ___________________ LIQUID/LIQUID - _______________ LIQUID/GAS - __________________ GAS/GAS - _____________________

17. Miscible vs. Immiscible Miscible: describes two or more liquids that are able to dissolve into each other in various proportions. Immiscible: describes two or more liquids that do not mix into each other.

18. Pure Substance or Mixture?

19. 2.2 MATTER AND ENERGY

20. Objectives Use the kinetic theory to describe the properties and structure of the different states of matter. Describe the energy transfers involved in changes of state. Describe the laws of conversation of mass and conservation of energy, and explain how they apply to changes of state.

21. Vocabulary Pressure Viscosity Energy Evaporation Condensation Sublimation

22. KINETIC MOLECULAR THEORY states: All matter is made of atoms or molecules that act like tiny particles. Atoms and molecules are always in motion. These tiny particles are always in motion. The higher the temperature, the faster the particles move. At the same temperature, heavier particles move slower than lighter particles.

23. The Kinetic Molecule - Quiz Molecules move by: A. Forces acting on them B. Their own internal energy C. Both of the above Cold causes molecules to: A. Move slower B. Lose energy C. Both of the above Heat causes molecules to: A. Move faster B. Gain energy C. Both of the above

24. Kinetic Theory Is useful tool for visualizing the differences between the three common states of matter: Solids Liquids Gases

25. The States of Matter are Physically Different The arrangement of particles in solids, liquids, and gases are differ in the distances and angles between molecules or atoms and in how closely these particles are packed together.

26. Gases Gases are free to spread in all directions. Gas expands to fill the available space. Under standard conditions of temperature and pressure the, particles of a gas move rapidly. Gases can exert pressure. Gases under pressure will escape their container if possible.

27. Solids A solid does not need a container to have a shape. The structure of a solid is very rigid, and the particles have almost no freedom to change position.

28. Liquid The particles in a liquid are close together, but they are not attracted to each other as strongly as they are in a solid. These particles have more freedom to move, which allows them to spread out on their own. Since liquids and gases can spread, they are both classified as FLUIDS.

29. Viscosity Liquids vary in the rate at which they spread. This property, viscosity, is determined by the attraction between particles in a liquid. The stronger the attraction, the more slowly the liquid flow, and the higher the viscosity will be.

30. Properties of the STATES OF MATTER are:

31. Energy�s Role Energy must be added to cause melting or evaporation. Energy is transferred in all changes of state. Changing state does not change composition or mass.

33. Laws The Law of Conservation of Mass Mass cannot be created or destroyed. The Law of Conservation of Energy Energy cannot be created or destroyed.

34. THE AMOUNT OF ENERGY DETERMINES THE STATE OF MATTER

35. Graphing Change of State

36. HOW CHANGE OF STATE AFFECTS MATTER: AMOUNT OF MASS ? ______ KIND OF MOLECULE ? ______ NUMBER OF MOLECULES? _____ VOLUME (space needed)? ______

37. REVIEW

38. Vocabulary Pressure: the force exerted per unit area of surface. Viscosity: The resistance of a fluid to flow. Energy: The ability to change or move matter. Evaporation: the change of a substance from a liquid to a gas. Condensation: the change of a substance from a gas to a liquid. Sublimation: the change of a substance from a solid to a gas.

39. 2.3 TWO PROPERTIES OF MATTER: CHEMICAL PHYSICAL How it reacts 1. Change of state Burn, decay, rust�. 2. Density, boil, cut, dissolve Form new substances 3. NO new substance 4.

40. Objectives Distinguish between chemical and physical properties of matter. Perform calculations involving density. Distinguish between chemical and physical changes in matter. Apply the laws of conservation of mass and conservation of energy to chemical and physical changes. Evaluate materials and their properties for different uses.

41. Vocabulary Chemical property Reactivity Physical property Melting point Boiling point Density Buoyancy Chemical change Physical change

42. Chemical Properties Chemical Property: the way a substance reacts with others to form new substances with different properties. Chemical properties describe how a substance acts when it changes, either by combining with other elements or by breaking apart into substances. Chemical properties involve the reactivity of elements or compounds. Chemical properties are related to the specific elements that make up substances. Reactivity: the ability of a substance to combine chemically with another substance. Flammability is a chemical property that describes whether substances will react in the presence of oxygen and burn when exposed to a flame.

43. Physical Properties Physical Properties: a characteristic of substance that can be observed or measured without changing the composition of the substance. You can use your senses to observe some of the basic physical properties of a substance: shape, color, odor, and texture. Other physical properties, such as melting point, boiling point, strength, hardness, and the ability to conduct electricity, magnetism, or heat are measured. Physical properties remain constant for specific pure substances.

44. Pure Substance At room temperature and atmospheric pressure, all samples of pure water are always colorless and liquid. Pure water is never something like powdery green solid. Water boils at 100 C and freezes at 0 C. At atmospheric pressure, pure water always has the same boiling point and melting point. A characteristic of ANY pure substance is that its boiling point and melting point are CONSTANT.

45. Boiling and Melting Point Boiling Point: the temperature at which a liquid becomes a gas below the surface. Melting Point: the temperature at which a liquid becomes a gas below the surface.

46. Density is a physical property Density: the mass per unit volume of a substance. Formula: D = m / V A substance that has a low density is sometimes referred to as being �light�. A substance that has high density is sometimes referred to as being �heavy�. By knowing the density of a substance, you can know if the substance will float or sink. The density of a liquid or a solid usually is reported in units of grams per cubic centimeter (g/cm3)

47. Buoyancy and Density Ice floats in water because ice is LESS DENSE than water. The tendency of a less dense substance, to rise and float in a more dense liquid, is called BUOYANCY. Buoyancy: the force with which a more dense fluid pushes a less dense substance upward.

48. Properties Help Determine Uses We use physical properties to help us select a substance that may be useful to us. Copper: is used in electrical power lines because of its good electrical conductivity. Concrete and glass: used as building materials because they change very little under most weather conditions. Materials can be chosen because: They stay in the same state and do not change under normal conditions. Some materials are used because they change physical states easily. Ability to change and combine to form new substances.

49. Chemical Changes Chemical change: are changes in composition by forming one or more new substances. A chemical change occurs when a compound breaks apart to form at least two other pure substances. The law of conservation of mass applies to all chemical changes because new atoms are not created, and old atoms are not destroyed.

50. Chemical Changes You know when a substance is undergoing a chemical change if you observe A change in odor A change in color

51. Physical Changes Physical changes do not change composition. During physical changes energy is always absorbed or released. After a physical change, a substance may look different, but the atoms that make up the substances are not changed or rearranged. Physical changes do not change all the properties of a substance. The law of conservation of energy applies to all physical changes because energy is not created nor destroyed.

52. REVIEW

54. Study for the TEST!!!!! Vocabulary words Identify as element or compound Identify physical or chemical property of a substance Identify if a change is physical or chemical Energy being absorbed or released Review questions A study guide will be posted on schoolnotes