1. GR. 7/8 SCIENCE Particle Theory of Matter

2. Review of Matter Everything is made of matter  Matter comes in 3 states  Solid (strong attraction)  Liquid (medium attraction)  Gas (low attraction) Matter takes up space  The amount of space something takes up is called volume

3. Particle Theory of Matter Describes the tiny particles that make up all matter in the universe and how they interact Four major elements of the theory: 1. All matter is made up of tiny particles we cannot see 2. Particles are always in motion 3. All pure substances are made up of their own atoms. 4. There are spaces between the particles 5. There is attraction between the particles

5. Temperature & Particles What is temperature?  the average heat energy (or speed) of the particles in a substance  This determines how “hot” or “cold” something is  Adding heat adds energy to the moving particles  Adding energy weakens the attraction between particles  Weakened attractions create more space between the particles

6. Temperature & Particles When temperature INCREASES, the speed of the particles also INCREASES When temperature DECREASES, the speed of the particles DECREASES

7. Changing States of Matter Adding or removing energy (such as heat) can cause a CHANGE in state  Causes particles to move faster or slower  Example:  Adding heat energy to snow can cause it to melt  Removing heat energy causes water to freeze

9. Assignment Hand in “Particle Theory Assignment” Eg. Adding heat to water Vaporization White mist (steam) and the water boils (bubbles)

10. Temperature and Volume

11. Temperature & Volume Adding heat causes matter to expand  As heat increases, volume increases  Particles move more and need to take up more space Cooling has the opposite effect  As heat decreases, volume decreases  Particles moves less and get closer together http://www.youtube.com/watch?v=sNvMfuOvHwg

12. Temperature & Volume Examples:  Pouring hot water over a stuck jar lid  Filling sidewalk joints with tar **Exception!**  Water expands when it cools  http://www.youtube.com/watch?v=T4GCShGvw-M http://www.youtube.com/watch?v=T4GCShGvw-M

13. Effects of temperature demonstration

14. Understanding Temperature

15. What is temperature?  How hot or cold something is How do we measure temperature?  Touch  Sight  Thermometers  First invented by Galileo Galileo’s thermometer was not very precise

16. Galileo’s Thermometer

17. Thermometers In 1742, Anders Celsius developed a scale for temperature, based on water  0 degrees = melting point of ice  100 degrees = boiling point of water

18. How does a thermometer work? Anyone know? Or can you guess?

19. Thermometers There are two main types of thermometers.  Mercury and alcohol Both of these liquids expand when heated because the particles move away from each other. This is why the mercury or alcohol seems to rise as it gets warmed, and sink as it cools.

20. Thermometers The different types of thermometers are used for different things. PropertyAlcoholMercury Temperature Range (that it works best at) -80°C - 110°C-39°C - 375°C Material management Easy to clean if there is a spill Difficult to clean if there is a spill. If it is absorbed through the skin it can endanger one’s health.

21. Assignment & activity In groups of 3, decide which type of thermometer would be used in each situation AND give a reason on why that thermometer would be better. - School - Hospital - Research Lab - Restaurant - Research station in Antarctica Complete “Challenger Analysis” assignment – individual.

22. Changes In Matter

23. Changes in Matter Melting Point  Temperature at which a solid changes state from solid to liquid  Examples:  Ice (water) = 0  C  Mercury = -38  C  Gold = 1065  C http://www.youtube.com/watch?v=Bg8yfetAD8s

24. Changes in Matter Boiling Point  Temperature at which a liquid changes state from liquid to gas  Examples:  Water = 100  C  Mercury = 357  C  Gold = 2856  C http://www.youtube.com/watch?v=0PIZUjhzrKw

25. Changes in Matter Boiling and melting points are properties of pure substances; they can change at different altitudes  Based on temperatures at sea level Boiling and melting points can be used to determine different substances  What if two substances have the same melting or boiling point?

26. Importance of Boiling & Melting Points Are you able to identify substances based ONLY on their boiling or melting point?  Not always! When is it important to know the boiling or melting point of a substance?  Examples?

27. Boiling and Melting Points

29. Plateau Explained The plateaus in the graph are called phase changes Melting (solid to liquid)  The temperature stays the same while a substance melts  0  C for water Boiling (liquid to gas)  The temperature stays the same while a substance boils  100  C for water

30. Boiling and Melting Points http://www.kentchemistry.com/links/Matter/Heati ngCurve.htm http://www.kentchemistry.com/links/Matter/Heati ngCurve.htm http://www.chemicool.com/boiling-points.html

31. Assignments Complete “Boiling & Melting Points in Real Life” Complete “Thermometers”

32. Review Graphing Horizontal axis – independent variable Vertical axis – dependent variable Scale – must go up by the same interval each time  You can skip count, but you can’t skip numbers  0, 2, 4, 6, 8, 10 – is fine  0, 2, 5, 9 – is not fine

33. LAB TIME!  We are going to do two labs over then next two classes.  I expect you to comply to all Lab safely policies and procedures.  If you do not follow instructions and the rules you will be removed from the lab immediately.  Your mark is dependant on your performance in the lab as well as the hand-in assignment.

34. Assignment Complete “Identifying Melting Points”

35. Heat or Temperature? Temperature  How cold or hot something is  Depends on how fast particles are moving  Matter with fast-moving particles have more energy and therefore a high temperature

36. Heat or Temperature? Heat  Energy that is transferred from matter with a high temperature to matter with a low temperature  Causes particles to increase speed when transferred **Energy is NOT a substance! It is a property that describes a substance’s ability to move, do work, or cause change

37. Heat or Temperature? Examples:  The heat from the hot tub was unbearable (heat refers to the energy present)  The temperature of the hot tub was 40  C (temperature refers to a measurement of the energy that is present)

38. Temperature vs. Heat Lab

39. Different Types of Heat Transfer

40. How is Heat Transferred? Conduction  Movement of heat through solids  Heat moves as particles collide with each other and pass on the energy  The closer the particles are, the better the conduction (transfer) of heat Example: pots on the stove Example: Metal conducts heat

41. Conduction Diagram Conduction Demo Will the different types of metals conduct electricity differently?

42. How is Heat Transferred? Convection  Movement of heat through fluids (liquids and gases)  Heat moves as particles collide while they flow past each other and pass it on  Usually a circular movement called a “current”  Convection currents are caused by warm fluids rising Example: ovens, radiators, ocean currents.

43. Convection Examples Conduct convection demo using water bottles and dye

44. How is Heat Transferred? Radiation  Transfer of heat energy through waves (not using matter or particles)  Called electromagnetic radiation  Infrared radiation, UV rays, radio waves, etc.  Waves can be absorbed and reflected  Example: dark objects absorb radiant energy when they are cool, and reflect it when they are hot  The sun emits radiant energy

45. Radiation Example

46. Heat Transfer Heat Conductors  Substances that readily allow the transfer of heat  Particles are closer together, so it is easier to collide and pass on the heat

47. Heat Transfer Heat Insulators  Substances that slow the transfer of heat from one area to another  More space between particles, so these substances actually slow down the heat from being passed on

48. Activity Make a list of some real-life conductors and insulators InsulatorsConductors Gloves Spray foam Contigo coffee mug Black shirt Glass/plexi glass insulation Rubber wool Person/hair Food Metal (Al, Cu) Water Paint

49. Heat & Friction Heat is called “thermal energy”  When particles come in contact with one another, energy can be transferred through friction  the force that resists motion when two substances come in contact with each other  Remember heat causes particles to move!  Examples of friction: bon fire phone book friction

50. Assignment Complete “Heat Transfer”

51. Energy Transformations Different types of energy can be transformed (changed) into other types of energy  Chemical energy  Mechanical energy  Nuclear energy  Electrical energy  Thermal

52. Activity Using the handout provided, fill in the chart describing each type of energy.

53. Types of Energy MechanicalThermalChemicalElectro- magnetic Nuclear

54. Bill Nye: Heat Bill Nye heat transfer

55. QUIZ!!! There will be a quiz on EVERYTHING from this unit so far

56. Pure Substances and Mixtures

57. Particle Theory & Substances Pure Substances  Made up of only one type of particle Mixtures  Two or more types of particles  There are 2 types of mixtures:  Solutions  Mechanical Mixtures

58. Types of Mixtures SolutionsMechanical Mixtures At least 2 parts (solute & solvent)2 or more parts Does not settle after standingSome parts may settle Appear to be one state (solid, liquid or gas) Each component is visible Homogeneous (looks all the same) Heterogeneous (can see different parts) Examples:

59. Solutions Solute  Substance that dissolves in another substance Solvent  Substance that dissolves the solute Substances are able to dissolve because the attraction between the particles of the solute can be broken and the solute particles become attracted to the solvent particles instead.  This new attraction makes them appear to be all one type of particle (homogeneous)

60. Animation of solution formation

61. Solutions in Everyday Life Predict the solute and solvent in the following solutions:  Ice cream  Air  Coke  Iced tea  Slurpee Work with your table partner to predict what you think the solvents and solutes are for each substance (there night be more then one)

62. Mechanical Mixtures Basic “mechanical mixtures” are obviously two substances (or more)  Ex. Oil and water  Ex. Salad  Ex. Soil Heterogeneous Mixtures  Suspension – particles slowly settle after mixing  Ex. Orange juice  Colloid – particles never settle  Ex. Fog

63. Assignment Complete “Attraction in Solutions”

64. Separating Mixtures

65. Situation: A community by the ocean would like to establish a small business that sells salt and pepper. Farmers are already growing peppers to be dried and used in the business but there are no salt mines within the vicinity. Someone has suggested obtaining the salt from the salt water of the ocean. How would this be done? 1. Evaporation – boil the solvent so it evaporates and leaves the solute behind  Ex. Boiling salt water will leave the salt behind.

66. Separating Mixtures Situation: To improve the icy road conditions, a sand-salt mixture has been used on the highways all winter. The spring cleanup crew has scooped up the mixture and would like to use the sand for road construction but the workers must first remove the salt. How could this be achieved? 2. Dissolving – add liquid to the mixture to dissolve one of the particle types and leave the other behind Ex. Pouring water in the sand/salt will dissolve the salt and leave just the sand.

67. Separating Mixtures Situation: A person would like to make a glass of fresh pulpless orange juice. What method could the person use? 3. Filtration – used to separate solutes from a liquid by pouring mixture through a filter with tiny holes (solute remains in filter).  Ex. Filter the pulped orange juice through the filter to remove the pulp.

68. Separating Mixtures Situation: Minute metal shards have fallen onto the sandy floor of a workshop. How could the owner clean the sandy floor of the dangerous metal pieces? 4. Magnetism – use a magnet to remove one type of particle (needs to be metal) Ex. Use the magnet to pick up any metal shavings.

69. Separating Mixtures Situation: The kitty litter box needs to be cleaned. All you have available is strainer with fairly large holes. How could you clean out the litter with your strainer? 5. Sifting – pour the mixture through a sieve with holes the right size to let one particle pass through but the other type remain in the sieve Ex. Poor the dirty kittle litter through the sieve, the large pieces will be separated out while the clean little falls through.

70. Separating Mixtures Situation: The milk that comes straight from the cow is often very high is fat. If we wanted to make the milk less fattening without using a lot of equipment how could we do it? 6. Density – let the mixture settle so that more dense particles will settle and less dense particles rise to the top  Ex. Let the milk sit. The cream and milk will separate and then you can take the cream off of the top. You will be left with low fat milk!

71. THE ABILITY OF A SOLUTE TO DISSOLVE IN A SOLVENT. Solubility

72. The ability of a substance to go into a solution by dissolving. Factors that affect solubility:  Particle size and surface area  The larger the surface area, the higher the solubility  Stirring/agitation  Stirring a substance will cause it to dissolve faster  Temperature  The higher the temperature, the faster the particles will move and the higher the solubility.

73. Demo Solubility Demonstration  Lets put 3 sugar cubes in 8 different beakers.  Compare the following…  Test 1: sugar cubes in tap water  Test 2: crushed sugar cubes in tap water  Test 3: sugar cubes in tap water plus stirring  Test 4: crushed sugar in tap water plus stirring  Test 5: sugar cubes in hot water  Test 6: crushed sugar cubes in hot water  Test 7: sugar cubes in hot water plus stirring  Test 8: crushed sugar in hot water plus stirring.

74. Demo Questions Which test do you believe will dissolve the slowest? Why? Which test do you believe will dissolve the fastest? Why?

75. Concentration in Solutions Concentration  Measure of how much of a substance is IN another substance  In solutions, concentration refers to how much SOLUTE is in the SOLVENT  The more solute in the solvent, the higher the concentration. Which one has the higher concentration? - 5 grams of ice tea powder in 100mL of solution - 10 grams of ice tea powder in 200mL of solution - 5 grams of ice tea powder in 50mL of solution

76. A B Which one has the higher concentration?

77. Saturated Solutions Saturation  The point at which a solution can no longer dissolve any more solute (at a specific temperature)  Particles’ attraction to each other becomes balanced, so no new solute particles can dissolve (can form attractions to other particles)  Any solute that does not dissolve is called the precipitate.

78. Saturated Solutions On an index card, write your name and the answer to this question. Solutions can have different levels of saturation, depending on temperature  Why?

79. Activity Using the drink powder provided and a spoon. Make yourself a cup of juice. If you need to add more powder or more water you may do so. Adjust it until it is just right!