OK, you ve probably seen the Bill Nye video and have learned that matter is everything and all stuff. That s right. Everything around you is matter.

Transcription

1 Matter & Chemistry

2 OK, you ve probably seen the Bill Nye video and have learned that matter is everything and all stuff. That s right. Everything around you is matter. In fact, anything that has weight and takes up space is matter.

3 Write it down: Matter Anything that has mass and volume. All objects are made of matter.

4 Forms of matter Matter comes in three common forms or phases: *SOLID *LIQUID *GAS Two additional, less known phases are: *PLASMA *BOSE-EINSTEIN CONDENSATE

5 Solids Solids have a definite shape and a definite volume. This means that solids keep their shapes and take up a set amount of space under normal conditions. Rocks, ice, salt crystals, & wood are all examples of solids.

6 Liquids Liquids do not hold their shapes; they take the shape of their container. Liquids have a definite volume. This means that a liter of water is a liter of water no matter what container it is in. Water, Pepsi, orange juice & oil are all examples of liquids

7 Gases Gases also take the shape of their containers. Gases do not have a definite volume. They will expand out to fill the entire container. (Think of a balloon) Oxygen, water vapor, Carbon Dioxide are all examples of gases.

8 Plasma the weird fourth stage A plasma is a gas that is made of atoms that are electrically charged (positive and negative ions). A plasma conducts electrical currents. It is estimated that 99% of the matter in the observable universe is in the plasma state

9 Bose-Einstein Condensate In a B-E condensate, the atoms in the solid begin to merge into each other. The atoms go from being trillions of individuals to one big clump. This happens only at a few billionths of a degree above absolute zero. Think of the M&M s melted together as the atoms in a B-E Condensate.

10 Molecules inside matter The molecules inside matter are in constant motion. Speed Slower Faster B.E.C. Solid Liquid Gas Plasma

11

12

13

14 Solid Liquid Gas

15 Changing Phase The atoms and molecules within matter are in constant motion. The energy that causes this is called kinetic energy the energy of motion.

16 Atoms and molecules with more kinetic energy moves faster and further apart. Atoms and molecules with less kinetic energy moves slowly and stay close together.

17 The TOTAL energy in all of the particles in a sample of matter is called Thermal energy. Thermal energy depends upon the number of particles in the sample as well as the energy each particle has. If you average the total kinetic energy of each individual particle in the sample, you have the sample s temperature. (This will be discussed later in the unit)

18 Matter can change state when thermal energy is absorbed or released. This is called, believe it or not, A Change in State

19 Molecular motion in Solids / Liquids / Gasses Ice Liquid water Steam

20 Rephrasing/Reviewing Kinetic energy is the energy that causes particles in a sample of matter to move. Thermal energy is the total kinetic energy of all particles in the sample of matter. Temperature is the average kinetic energy of the particles in the sample of matter.

21 When a cold object and a hot object come in contact, the thermal energy is transferred from the hot to the cool object. Thus, when an object is heated, the particles in it begin to move faster, increasing its temperature. Heat is defined as the movement of thermal energy from a warmer object to a cooler one.

22 Phase change diagram Solid Liquid Gas

23 Phase change diagram Sublimation Melting Evaporation Add Heat Add Heat Solid Liquid Gas Remove Heat Freezing Remove Heat Condensation Crystalization or desublimation

24 Vocab Review Melting: Solid becoming a liquid. Add energy. Evaporation: Liquid becoming a gas. Add energy. Freezing: Liquid becoming a solid. Remove energy. Condensation: Gas becoming a liquid. Remove energy.

25 More vocab. Sublimation: Solid becoming a gas, skipping the liquid phase. Add energy. Crystallization or Desublimation: Gas becoming a solid, skipping the liquid phase. Remove energy. General Terms: Solidification: to become a solid. Liquefaction: to become a liquid. Vaporization: to become a gas.

26 Sublimation and Crystallization

27 Properties of matter Matter is described using three properties physical, chemical, and biological.

28 Physical Properties Physical properties of matter that can be observed and measured using your five senses, without changing the composition of a substance.

29 Physical Properties Examples of physical properties include: size color shape and texture state of matter melting and boiling points does it conduct electricity? mass, volume, density

30

31 More Vocabulary Solubility: Ability to dissolve in water or another liquid. Malleable: Easily pounded into shapes. Ductile: Easily made into wire. Viscosity: Ability of a liquid to flow. Examples: High Viscosity = Corn syrup.

32 Chemical Properties Chemical properties of matter are often not easily observed. Chemical properties describe how the chemicals inside the matter react with other chemicals. When trying to figure out the chemical properties of matter ask yourself some questions:

33 Chemical property questions: Will it burn? Paper will, concrete will not. Therefore, a chemical property of paper is that it will burn. A chemical property of concrete is that it will not burn. Can I eat it? - You can consume an orange and get nutrition from it. You can physically eat a rock, but it does nothing for you. Thus, a chemical property of an orange is that it is edible.

34 Chemical properties More often than not, chemical properties indicate how the chemical will react with other chemicals. We will discuss this further in the unit.

35 Biological properties Biological properties of matter tell whether it is living, non-living, or dead.

36 Measuring Matter Matters! As we said, physical properties of matter include measurements. The important measurements of matter we are going to deal with now include Mass, Volume, Density, and Temperature.

37 MASS Mass: A measurement of the amount of matter inside an object. Mass is often thought of being the same as weight. This is not true. Weight depends upon the gravitational force exerted upon an object.

38 Weight - The downward force exerted on an object due to gravity.

39 Mass vs. Weight Mass is measured using a balance. Weight is measured using a scale.

40 Volume How much soda fits into a 2-liter bottle? Why does the tub overflow if it is too full when you climb in?

41 Volume Volume can answer both of these questions. Volume is the amount of space taken up by an object OR the amount of space inside a container.

42 Volume Facts: Volume is measured in some form of liters, commonly Milliliters (ml). Volume can also be measured in cubic centimeters. 1 cm 3 water = 1ml water. Many items are sold by volume such as gasoline, soda, milk, and shampoo. The average volume of a bathtub is 40 gallons or liters.

43 Most Important fact!!! When dealing with volume, the number one rule is: NO TWO OBJECTS CAN OCCUPY THE SAME SPACE AT THE SAME TIME!

44 Volume Only the bottom bags are taking up space on the pallet. The box and the soda bottle both have space inside them.

45 Measuring volume When measuring volume, you can use different methods depending upon the shape of the item. If you are attempting to find the volume of a cubic item, you only need to measure the length, width, and height of the object and multiply them (volume = L x W x H)

46 Measuring with a ruler Length x Width x Height Height Width Length If L = 10cm, W= 10 cm, and H = 10 cm, what is the volume of this Rubic s cube?

47 Measuring with a ruler 10 x 10 x 10 = 1000 cm 3 The answer is given in cubic centimeters, cm 3. Remember: 1 cm 3 water = 1ml water.

48 Measuring irregular shapes What if you wanted to find out the volume of a rock? A Ball? A ring?

49 Measuring irregular shapes To measure an object with an odd or irregular shape, you cannot use a ruler. The method used for finding the volume of irregular shapes is called the Water Displacement Method. The tools required for this method are a graduated cylinder and water.

50 Measuring irregular shapes 1) Find a graduated cylinder that will be large enough to fit the object(s) being measured. 2) Fill this graduated cylinder enough so that when placed in the graduated cylinder, the object will be fully submerged in the water.

51 Measuring irregular shapes 3) After filling the graduated cylinder, record the volume of the water. 4) Next, carefully place the object in the graduated cylinder and record the new volume of water.

52 Measuring irregular shapes 5) To find the volume of the irregularly shaped object, subtract the volume of the water alone from the volume of the water and object.

53 What is the volume of this stone?

54 Meniscus - the curve seen at the top of a liquid because of its attraction to its container. Important fact!!

55 Important fact!! A meniscus is what happens when you put a liquid into a container. When you put water in a beaker or test tube, you see a curved surface. With most liquids, the attractive force between the liquid and the container is greater than the attraction between the individual liquid molecules. So the liquid "sticks" to the side of the container.

56 Meniscus Water has a slight electric charge which causes it to stick to the side of the glass. This is called the meniscus.

57 Density Density is defined as: An object s mass per unit of volume. In other words, what is its mass compared to its size. An objects density tells us how tightly packed the molecules inside are. The more tightly packed the molecules of an object, liquid or gas are, the more dense we say they are.

58 Density Density is usually expressed in grams/milliliters or grams/cubic centimeters. The standard for density is water. Water s density is 1 gram/milliliter. That means that 1 ml of water will have a mass of 1 gram.

59 Density Which item below would be the most dense? Which would be the least dense? v WHY?

60 Finding Density In order to find the density of an object, you must first know its mass and volume. To find density, you divide the object s mass by the volume and that tells you the density. The formula for density is: Density = Mass/volume or D=M/V

61 Examples of Density The mass of a rock is 20g and its volume is 4ml. What is its density? The mass of a rock is 20g and its volume is 4ml. What is its density?

62 Sink or Float? Any object that has a density of less than 1g/ml is going to float when placed in water. Any object with a density that is greater than 1g/ml is going to sink. With this in mind, how could you guess the density of a piece of foam? Oops!

63 Sink or Float? LESS dense objects (things that are less packed together) float on top of things that are MORE dense (more packed together); this includes things like liquids and gases and circumstances like a cheese doodle in rice. As long as an object is less dense than the substance it is in, it will float. If an object is too dense it will sink to the bottom. The size of the object does not matter! *LARGE, light (less dense) object will FLOAT. *Small, heavy (more dense) objects will sink.

64 Formula fun! To find density: D=M/V To find Mass: M= D x V To find Volume: V= M/D

65 Review What tool is used to determine mass? What method would you use to find the volume of a basketball? What is the formula for finding density? How is mass different from weight?

66 Temperature Temperature is the average kinetic energy of the particles in the sample of matter. As you remember from Bill Nye, all molecules of any substance are constantly moving. The faster the molecules are moving, the warmer the substance is.

67 Temperature Scientists use a thermometer to measure temperature.

68 Temperature is measured with several different scales. Temperature

69 Temperature - F In the United States, we use the Fahrenheit Scale F. In the Fahrenheit scale, 32 0 F is the freezing point of water F is the boiling point of water F is Absolute Zero.

70 Temperature - C the Celsius scale is used by almost every other country 0 C In the Celsius scale, 0 0 C is the freezing point of water C is the boiling point of water C is Absolute Zero.

71 Temperature - K Scientists use a different scale called the Kelvin Scale K. ( NOTE: the 0 symbol is not used in the Kelvin scale) In the Kelvin Scale, K is the freezing point of water K in the boiling point of water. 0 K is Absolute Zero.

72 Converting scales Kelvin to Celsius C = K Celsius to Kelvin K = C Kelvin to Fahrenheit F = K Fahrenheit to Kelvin K = ( F ) 5 9 Celsius to Fahrenheit F = C x Fahrenheit to Celsius C = F - 32 / 1.8

73 Temperature Heat moves in a predictable flow from warmer objects to cooler objects until all objects are at the same temperature. In other words, heat moves from high concentration (the heat source) to low concentration. COLD NEVER MOVES! Coldness is simply an absence of heat, or slow molecular motion.

74 Heat moves in three ways: Conduction Convection Radiation

75 Movement of Heat - Conduction Conduction is the transfer of heat from one object to another through direct contact. (touching) Conduction is the simplest form of heat transfer.

76 Movement of Heat - Conduction The rapidly moving atoms of the hot burner bump against the atoms that make up the pan, making those atoms move faster.

77 Movement of Heat #2 - Convection Convection is the method of heat transfer in liquids or gases by means of currents. As particles get heated they start to move faster. As the particles move faster, they move farther apart and the object becomes less dense. Less dense objects move to the surface of more dense objects. That explains why the warmer water when swimming is at the top. This also explains how a hot air balloon works.

78 Convection in a Pot Water at the bottom warms, becomes less dense and rises to the top.

79

80 As the water at the bottom of the beaker gets hotter, it rises to the top. This makes the cooler water sink to the bottom where It begins to heat. When it gets hot enough, it rises and continues the cycle.

81 Movement of Heat - Convection Most likely your home is heated by convection. A radiator heats up the air near it. When this air rises, the cool air sinks and begins to warm up. When it rises it is replaced again by cooler air.

82

83 Conduction and Convection

84 Movement of Heat - Radiation Radiation transfers heat through space to other objects by infrared waves. Heat sources such as the sun or a hot wood stove send out these invisible infrared waves.

85 Movement of Heat - Radiation The earth receives heat from the sun by radiation.

86 Movement of Heat - Radiation The heat from the sun can warm the ground even though it is 186,000 miles away!!

87 All things emit some form of heat radiation. This can be seen with an infrared camera. Hotter parts are red, and cooler are blue.

88 Movement of Heat - Radiation Sitting by a fire, you feel heat waves.

89

90 Conductors and insulators

91 Conductors Some materials readily accept the transfer of heat energy. Any material that allows heat to pass through it easily is called a Conductor. Heat travels easily through some materials like copper, aluminum, and most metals.

92 Conductors Why are pots and pans made out of metal and not wood or plastic?

93 Insulators Some materials do not allow heat to pass through very well. These are called insulators. The handles on pots and pans are often made of wood and plastic since these materials do not allow heat to pass through them easily. Liquids, gases, and most non-metallic solid materials like wood and plastic are good examples of insulators.

94 Conductors move heat easily because the atoms and molecules in a conductor are generally more dense than insulators. Conductor Insulator

95 Buy New Windows!

96

97 Why do you think people use wooden spoons when cooking? What purpose do the pot holders serve?

98 Coats, hats, and gloves trap our body heat close to us. The materials inside them insulate us from the cold.

99 Down Coats The feathers in a down coat or comforter trap the air molecules in the many fibers and prevent heat from moving.

100 Insulating your Home saves Money and Energy! Poorly Insulated Home Well Insulated Home

101 As air molecules attempt to move through the empty space, there is nothing to slow them down or stop convection currents and the movement of heat. As air molecules attempt to move through the fiberglass, the fibers slow them down or trap them, slowing or stopping convection currents and the movement of heat.

102 The better insulated your home is, the less heat loss that occurs through the walls. The less heat loss you have, the warmer your house stays and the furnace doesn t run as often. If your furnace doesn t run as often, you save electricity, fuel, and MONEY!! If you save money, you have more to buy your favorite science teacher presents!!

103 Review: What is Heat? What is temperature? How does heat move? How is a conductor different from an insulator? F = 0 C? 100 K = 0 C? What else do YOU feel needs review?

104 What is Matter made of? Matter is composed of tiny particles called atoms. Now would be a good time to view the exciting, spectacular, Power Point show entitled Atoms