1. Bellwork Chapter Pre-test:
1. What instrument would you use to measure temperature? Thermometer
2. Which of the following is a unit of volume?
A. atmosphere
B. gram
C. meter
D. liter D.
3. What characteristic of matter can you measure using a graduated cylinder? Volume
4. The sides of a cube are 2 cm by 2 cm. What is the volume of the cube? 8 cm3
5. What additional quantity would you need to calculate the density of the cube in question 4? Mass
6. Which of the following topics is not studied in chemistry?
A. Composition of matter
B. reactions of substances
C. properties of materials
D. motion of large objects. D.

2. Physical science Chapter 2
Properties of Matter

3. Lab Groups of three-four will be made
Each group will be provided 5 materials, a rubber band, a steel paper clip, a copper prong, wooden pencil or toothpick, and a graphite pencil filler.
Determine the properties or characteristics of the materials by touching, smelling, and looking at them.
Record these properties in a table/chart.
After you record these properties, write a description of each material that could be used to clearly identify it.

4. Bellwork
Finish the lab quickly so we can discuss your descriptions.

5. Possibilities Rubber’s elasticity Copper’s color Steel’s shininess
Wood’s brittleness
Graphite’s ability to leave a mark
Description:
Copper is a gold-ish solid that is flexible enough to be shaped and bent

6. Section objectives
1. Classify pure substances as elements or compounds.
2. Understand why are elements and compounds are classified as pure substances
3. Understand how mixtures differ from pure substances.
4. Know what the main difference is among solutions, suspensions, and colloids.

7. Heterogeneous mixture
Matter
Substance
Element
Compound
Mixture
Heterogeneous mixture
Homogenous Mixture

8. Intro Your book uses the example of a care label on your clothes.
Why is it there?
A tendency to wrinkle is a property of cotton, the tendency to not wrinkle is a tendency of polyester, the tendency to shrink when washed is a property of wool.
They all have different properties because they have different compositions.
These compositions can be broken into pure substances and mixtures

9. Pure substances
Matter that always has the same composition is classified as a pure substance, or substance
Every sample of a given substance has the same properties because a substance has a fixed, uniform composition.
Salt is a composition of sodium and chloride
Substances can be classified into two categories, elements and compounds
Matter
Substance
Elements
Compounds

10. Elements There are only about 100 elements
Element: a substance that cannot be broken down into simpler substances
An atom is the smallest particle of an atom
An element has a fixed composition because it contains only one
type of atom.

11. Elements No two elements contain the same type of atom.
Most elements are solids at room temperature (20 C, 68 F)

12. Examples
Aluminum

13. Example
Carbon

14. Elements Some elements are gas at room temperature
Oxygen and nitrogen are the main gases we breathe

15. Bellwork Draw the diagram classifying the different types of matter
What are elements made of?
What form are most elements in at room temperature?

16. Liquid Elements
Only two elements that are liquid at room temperature: Bromine and mercury, both are very poisonous

17. Symbols
The symbols for elements are similar to why scientists use the SI system of measurement.
Many symbols are based on the Latin name for the element and all scientists agree on the symbol for each element
*project!: Choose an element you are unfamiliar with. Research the origin of the symbol. Then, research the application or use of the element. Write at least a paragraph detailing this information and turn it in on Thursday

18. Compounds Someone read the first paragraph under Compounds on pg. 40
A compound is a substance that is made from two or more simpler substances. The simpler substances are either elements or other compounds

19. Compounds continued
THE PROPERTIES OF A COMPOUND DIFFER FROM THOSE OF THE SUBSTANCES FROM WHICH IT IS MADE
Water is a compound made up of the elements hydrogen (H) and oxygen (O)
Both of these elements are gases at room temperature, but water is a liquid
Hydrogen can fuel a fire and oxygen is needed to keep it going, but water is used to put it out

20. COMPOUNDS
COMPOUNDS ALWAYS CONTAIN TWO OR MORE ELEMENTS JOINED IN A FIXED PORTION
Silicon dioxide, for example, is the compound found in most light colored sand
It is made from the elements silicon ( a gray solid) and oxygen.
It is always made with two oxygen atoms for each silicon atom. (di means 2) Same for water

21. Mixtures
Mixtures tend to retain some of the properties of their individual substances
But the properties of a mixture are less constant than the properties of a substance
The properties of a mixture can vary because the composition of a mixture is not fixed.

22. On your own
Read pages 41-44
Create a chart with descriptive visuals and examples to help you classify the different types of mixtures
Heterogeneous
Homogeneous
Solutions
Suspension
Colloid
When you finish, complete section 1 in your workbook

23. Types of mixtures Mixtures are combinations of substances
The composition of the substances (unlike compounds) are not constant
Example: salsa
Heterogeneous mixtures: the parts that make up the mixture are noticeably different
Example: sand

24. Bellwork
Think of a homogeneous and a hetergeneous mixture

25. Heterogeneous Mixtures Hetero (different) genus (kind)

26. Homogeneous mixtures
Homogeneous mixtures: the substances are so evenly distributed that it is difficult to distinguish one substance from another
Example: a stainless steel spoon is a homogeneous mixture of iron, chromium and nickel

27. Homogeneous Mixtures

28. Solutions, Suspensions, Colloids
Based on the size of its largest particles, a mixture can be classified as a solution, suspension, or a colloid

29. Solution
Solution: when substances dissolve and form a homogeneous mixture
Example: sugar dissolved in water
Characteristics:
Particles are too small to settle out of the solution
Particles cannot be trapped by a filter
Particles are too small to scatter light

30. Solution

31. Suspension “Shake Well”
Suspension: a heterogeneous mixture that separates into layers over time
Example: Sand and water
Characteristics:
Particles will settle
Particles can be filtered
Particles are large enough to scatter light

32. Suspension

33. Colloid
Colloid: contains some particles that are intermediate in size between the small particles in a solution and the larger particles in a suspension.
Example: homogeneous milk
Characteristics:
Particles do not separate into layers
You cannot filter to separate parts of a colloid
Particles are large enough to scatter light

34. Colloid

35. Mixture Solution Suspension Colloid Heterogeneous Homogeneous
Combination of substances
Solution
When substances dissolve in a homogeneous mixture, sugar water
Suspension
Heterogeneous mixture that separates into layers, sand and water
Colloid
Homogeneous mixture with intermediate particles, milk, fog
Heterogeneous
Parts are noticeably different , sand
Homogeneous
Parts are evenly distributed, stainless steel spoon

36. Bellwork 8-29
Give an example of a solution, suspension, and a colloid

37. Examples of physical properties
Physical property: any characteristic of a material that can be observed or measured without changing the composition of the substances in the material.
Viscosity
Conductivity
Malleability
Hardness
Melting point
Boiling point
Density

38. Viscosity
Viscosity: the tendency of a liquid to keep from flowing-its resistance to flowing
The greater the viscosity the slower the liquid flows

39. Viscosity Viscosity usually decreases when heated
Importance? Think motor oil…

40. Conductivity Conductivity: a material’s ability to allow heat to flow
Materials with high conductivity (metals) are conductors
If a material is a good conductor of heat it will usually do the same for electricity
So why do we stir soup with a wooden spoon?

41. Conductive materials

42. Malleability
Malleability: the ability of a solid to be hammered without shattering.
Most metals are malleable
Solids that shatter when struck are brittle
Give an example of a malleable and brittle material.

43. Malleability

44. Hardness Hardness: how hard a material is
To compare hardness you can try to scratch one object with another
Diamond is the hardest material known

45. Hardness

46. Melting and boiling points
Melting Point: The temperature at which a substance changes from a solid to liquid
Boiling Point: The temperature at which a substance boils
What are the melting and boiling points of water in Celsius?
Are there any factors that can affect boiling point?

47. Melting/Boiling Points

48. Density Density: can be used to test the purity of a substance
Examples include methanol for bike racing

49. Using Physical Properties to Identify Materials
1. Decide which properties to test
2. Perform tests on unknown samples
3. Compare data results with data reported for known materials
Example: crime investigation

50. Recognizing Physical Change
Physical Change: A physical change alters the
form of a substance, but does not change it
to another substance.

51. Using Properties to Choose Materials
Properties determine which materials are chosen for which uses.
Wood shoelaces?

52. Using Properties to Separate Mixtures
Two properties are used to separate:
Filtration
Distillation
Filtration: a process that separates materials based on the size and of their particles.
What are some examples of filtration?

54. Homework Finish section 1 in your work/study book
Finish your research on your symbol

55. Chemical Properties
Chemical property: any ability to produce change in the composition of matter
Chemical properties can only be observed when the substances in a sample of matter are changing into different substances.
Example: Paraffin wax in a candle (made of compounds containing hydrogen and carbon).
As the compounds burn they combine with oxygen and form water and carbon dioxide

56. Chemical Properties
Flammability and Reactivity are two chemical properties of matter.
Flammability: a material’s ability to burn in the presence of oxygen

57. Why does it matter?
Think of some reasons why the flammability of a material or substance is important?

58. Reactivity
Reactivity: how readily a substance combines with other substances
Oxygen and iron are highly reactive substances.
What happens when iron reacts with oxygen and water?
What are some other materials that rust?

59. Rust

60. Reactivity Nitrogen has a low reactivity
Because of this it is used to displace the reactivity of other substances
Example: water tanks that stabilize ships are filled with seawater.
The oxygen in the water reacts with the iron in the steel and creates rust
Japanese engineers have pumped nitrogen in these tanks to displace the oxygen and decrease rust.

61. Recognizing chemical changes
Chemical change occurs when a substance reacts and forms one or more new substances.
Can you think of examples of chemical change?

63. Recognizing change Think of things that change chemically.
What are some “side effects” of chemical change?

64. Recognizing Chemical Change
3 types of evidence for chemical change:
1. Change in Color
2. Production of gas
3. Formation of a precipitate

65. Change in Color
A change in color is a clue that a chemical change has produced at least one new substance
Copper + water+ Oxygen=Patina

66. Production of a Gas
Can you think of an example of a production of gas when compounds or substances are combined?

67. Production of Gas Many gas reactions include carbon dioxide.
When baking soda and vinegar are combined they form bubbles of carbon dioxide
Baking soda in a cake combines with an acid and creates bubbles which make the cake rise

69. Formation of a Precipitate
Any solid that forms and separates from a liquid mixture is called a precipitate
What are some examples?

70. Formation of a Precipitate
When acid is added to milk the proteins undergo a chemical change that alters their structure, causing them to stick together in clumps
These clumps are cheese!

72. Chemical or Physical Change?
Always ask, “are different substances present after the change takes place?”
If not, then it is a physical change
Chemical change= the composition of the matter changes
Physical change=the composition of the matter remains the same.
What are some examples of physical change that have evidence of chemical change?

73. Video for Chemical and Physical Change