1. The Nature of Matter 15 Chapter 15: Classification of Matter
Table of Contents 15
The Nature of Matter
Chapter 15: Classification of Matter
15.1: Composition of Matter
15.2: Properties of Matter
15.3: Physical vs. Chemical Changes
15.4:

2. A substance can be either an
Composition of Matter
15.1
Pure Substances
Materials are made of a
pure substance or a
mixture of substances.
A pure substance, or simply a substance, is a type of matter with a fixed composition.
A substance can be either an
element or a compound.

3. Composition of Matter
15.1
Elements
All substances are built from atoms. If all the atoms in a substance have the same identity, that substance is an element.
The graphite in your pencil point and the copper coating of most pennies are examples of elements.

4. Substances Elements Compounds H O K He N B Na S P Li Cu Be C Au Ar H2O
NaCl
CO2
HCl

5. Elements ELEMENTS - SIMPLEST FORM OF A PURE SUBSTANCE
Elements  CAN NOT BE CHANGED INTO SIMPLER SUBSTANCES BY HEATING OR BY ANY CHEMICAL PROCESS
- SMALLEST PART IS CALLED AN _____
*Which means – Uncutable or Indivisible
ATOM

6. Atoms - ALL ATOMS OF THE SAME ELEMENT ARE ALIKE
- ATOMS OF DIFFERENT ELEMENTS
ARE DIFFERENT
- EACH ELEMENT IS REPRESENTED BY
A CHEMICAL SYMBOL

7. CHEMICAL SYMBOLS ARE A SHORTHAND WAY OF REPRESENTING AN ELEMENT
Symbols are always written with first letter capitalized and if there is a second letter is will always be lower case
C : CARBON H : HYDROGEN
Na : SODIUM O : OXYGEN
Cl : CHLORINE Au : GOLD
He : HELIUM N : NITROGEN
Ne : NEON Pu : PLUTONIUM
Es : EINSTEINIUM Eu : EUORPIUM
LATIN NAMES, FAMEOUS SCIENTIST, PLACES, PLANETS, AND COUNTRIES ARE OFTEN USED TO CREATE AN ELEMENT SYMBOL

8. About 92 elements are found on Earth.
More than 20 others have been made in laboratories, but most of these are unstable and exist only for short periods of time.
About 92 elements are found on Earth.

9. Compounds COMPOUNDS - PURE SUBSTANCES MADE UP OF MORE THAN ONE ELEMENT
Joined in the same RATIO
Exp: Water (H2O), Carbon Dioxide (CO2),

10. Compounds CAN BE BROKEN DOWN INTO SIMPLER SUB.S’ !!!
PROPERTIES OF COMPOUNDS ARE DIFFERENT THAN THE PROPERTIES OF THE ELEMENTS IN THEM :
NaCl Table Salt
*MOLECULES - MAKE UP MOST COMPOUNDS
- TWO OR MORE ATOMS CHEMICALLY BONDED
TOGETHER

11. Molecules cont. -ALL MOLECULES OF THE SAME COMPOUND ARE ALIKE
- IS THE SMALLEST PART OF A COMPOUND WITH ALL THE PROPERTIES OF THAT COMPOUND
-ALL MOLECULES OF THE SAME COMPOUND ARE ALIKE

12. Composition of Matter
15.1
Compounds
Can you imagine yourself putting something made from a slivery metal and a greenish-yellow, poisonous gas on your food?

13. Composition of Matter
15.1
Compounds
Table salt is a chemical compound that fits this description. Even though it looks like white crystals and adds flavor to food, its components—sodium and chlorine—are neither white nor salty.

14. MATTER THAT CONSIST OF TWO OR MORE SUBSTANCES MIXED TOGETHER
Mixtures
MATTER THAT CONSIST OF TWO OR MORE SUBSTANCES MIXED TOGETHER
BUT
NOT
CHEMICALLY COMBINED !!!

15. Which is Which ? Substance or Mixture
    When you see distilled water, it's a pure substance. That fact means that there are just water molecules in the liquid.

16. The tap water is the mixture and Distilled water is a Substance  which is a type of Compound

17. Mixtures – Background Info
There are an infinite number of mixtures.
Anything you can combine is a mixture.
(even the above sentence is a mixture.)
Don’t copy the statement below in yellow just read it.
Think of everything you eat. Just think about how many cakes there are. Each of those cakes is made up of a different mixture of ingredients. Even the wood in your pencil is considered a chemical mixture. There is the basic cellulose of the wood, but there are also other compounds in that pencil.

18. 15.1
Mixture
A Mixture, such as the pizza or soft drink shown, is a material made up of two or more substances that can be easily separated by physical means.

19. HETEROGENEOUS MIXTURE - DOES NOT APPEAR TO BE THE SAME THROUGHOUT
Composition of Matter
15.1
Heterogeneous Mixtures
Unlike compounds, mixtures do not always contain the same proportions of the substances that make them up.
A mixture in which different materials can be distinguished easily is called a heterogeneous (he tuh ruh JEE nee us) mixture.
HETEROGENEOUS MIXTURE - DOES NOT APPEAR TO BE THE SAME THROUGHOUT

20. Heterogeneous Mixtures
Composition of Matter
15.1
Heterogeneous Mixtures
Most of the substances you come in contact with every day are heterogeneous mixtures. Some components are easy to see, like the ingredients in pizza, but others are not.
For example, the cheese in pizza is also a mixture, but you cannot see the individual components.

21. Composition of Matter
15.1
Homogeneous Mixtures
Soft drinks contain water, sugar, flavoring, coloring, and carbon dioxide gas.
Soft drinks in sealed bottles are examples of homogeneous mixtures.
Steel is a homogeneous mixture

22. Homogeneous Mixtures
A homogeneous (hoh muh JEE nee us) mixture contains two or more gaseous, liquid, or solid substances blended evenly throughout.
oil or vineagar is an example of a homogeneous mixture wherein the composition is uniform throughout the entire thing

23. Composition of Matter
15.1
Homogeneous Mixtures
Another name for homogeneous mixtures like a cold soft drink is solution.
A solution is a homogeneous mixture of particles so small that they cannot be seen with a microscope and will never settle to the bottom of their container.

24. Colloids

25. Milk is an example of a specific kind of mixture called a colloid.
Composition of Matter
15.1
Colloids
Milk is an example of a specific kind of mixture called a colloid.
A colloid (KAH loyd) is a type of mixture with particles that are larger than those in solutions but not heavy enough to settle out.

26. Examples of colloids
These are just a few of the many examples of colloids, both man-made and naturally occuring.
Aerosols:
Man-made: Aerosol sprays, insecticide spray, smog. Natural: Fog, clouds.
Solid aerosol:
Natural: Smoke, dust.
Foam:
Man-made: Shaving lather, whipped cream.
Emulsions:
Man-made: Mayonnaise, cosmetic lotion, lubricants. Natural: Milk.
Sols:
Man-made: Paint, ink, detergents, rubber (a latex - also occur naturally).
Solid foams:
Man-made: Marshmallow, styrofoam, insulation, cushioning.
Gels:
Man-made: Butter, jelly.
Solid sols:
Man-made: Certain alloys. Natural: Pearl, opal

27. Detecting Colloids
One way to distinguish a colloid from a solution is by its appearance.
Fog appears white because its particles are large enough to scatter light.
Sometimes it is not so obvious that a liquid is a colloid.
You can tell for certain if a liquid is a colloid by passing a beam of light through it.

28. Composition of Matter
15.1
Detecting Colloids
A light beam is invisible as it passes through a solution, but can be seen readily as it passes through a colloid. This occurs because the particles in the colloid are large enough to scatter light, but those in the solution are not.
This scattering of light by colloidal particles is called the Tyndall effect.

30. Guess what this is and get a sticker!
You must raise your hand.

31. Suspensions
Some mixtures are neither solutions nor colloids. One example is muddy pond water.
Pond water is a suspension, which is a heterogeneous mixture containing a liquid in which visible particles settle.
Fine sand in water
Paint
Dust in air
droplets of oil in air
oil and waterfine
Italian Dressing
Some examples:

32. Composition of Matter
15.1
Suspensions
The table summarizes the properties of different types of mixtures.

34. Solutions remain constantly and uniformly mixed.
Composition of Matter
15.1
Homogeneous Mixtures
Solutions remain constantly and uniformly mixed.

35. Section Check
15.1
Question 1
A _______ is a type of matter with a fixed composition.
A. colloid
B. mixture
C. substance
D. solution

36. Section Check
15.1
Answer
The answer is C. A substance can be either an element or a compound.

37. Question 2 15.1 How many elements are found on Earth? A. 5 B. 10 C. 30
Section Check
15.1
Question 2
How many elements are found on Earth?
A. 5
B. 10
C. 30
D. 90

38. Section Check
15.1
Answer
The answer is D. About 92 elements are found on Earth, and more than 20 have been made in laboratories.

39. Question 3 15.1 How are compounds different from mixtures?
Section Check
15.1
Question 3
How are compounds different from mixtures?

40. Section Check
15.1
Answer
The atoms in compounds are combined in fixed proportions and cannot be separated by physical means. A mixture is made of two or more substances that can be easily separated by physical means.

41. Part 2
Properties of Matter

42. Properties of Matter
15.2
Physical Properties
Any characteristic of a material that you can observe without changing the identity of the substances that make up the material is a physical property.
Examples of physical properties are color, shape, size, density, melting point, and boiling point.
Viscosity – The tendency of a liquid to keep from flowing.

43. Viscosity heated The Greater the Viscosity =
the S L O W E R the liquid moves.
Viscosity usually decreases when the liquid is ______________.
heated

44. Conductivity
Which spoon would you leave in a pot of boiling water?
Wooden or Metal ?
A material’s ability to allow heat (or electricity) to flow is known as Conductivity.

45. Malleability
The ancient gold objects found in tombs in Greece were made by tapping GOLD with a hammer and punch. Gold can be shaped because it is malleable.
Malleability - is the ability of a solid to be hammered without shattering.
Most metals are malleable.

46. Properties of Matter
15.2
Appearance
How would you describe a tennis ball? You could begin by describing its shape, color, and state of matter.
You can measure some physical properties, too. For instance, you could measure the diameter of the ball.

47. Properties of Matter
15.2
Behavior
Some physical properties describe the behavior of a material or a substance.
Attraction to a magnet is a physical property of the substance iron.
Every substance has a specific combination of physical properties that make it useful for certain tasks.

48. Using Physical Properties to Separate
Properties of Matter
15.2
Using Physical Properties to Separate
The best way to separate substances depends on their physical properties.
Size is one physical property often used to separate substances.

49. Using Physical Properties to Separate
Properties of Matter
15.2
Using Physical Properties to Separate
Look at the mixture of iron filings and sand shown.
You probably won’t be able to sift out the iron filings because they are similar in size to the sand particles. What you can do is pass a magnet through the mixture.

50. Using Physical Properties to Separate
Properties of Matter
15.2
Using Physical Properties to Separate
The magnet attracts only the iron filings and pulls them from the sand. This is an example of how a physical property, such as magnetic attraction, can be used to separate substances in a mixture.

51. The Identity Remains the Same
Properties of Matter
15.2
Physical Change
The Identity Remains the Same
A change in size, shape, or state of matter is called a physical change.
These changes might involve energy changes, but the kind of substance—the identity of the element or compound—does not change.

52. The Identity Remains the Same
Properties of Matter
15.2
The Identity Remains the Same
Iron is a substance that can change states if it absorbs or releases enough energy—at high temperatures, it melts.
Color changes can accompany a physical change, too.

53. The Identity Remains the Same
Properties of Matter
15.2
The Identity Remains the Same
For example, when iron is heated it first glows red. Then, if it is heated to a higher temperature, it turns white.

54. Using Physical Change to Separate
Properties of Matter
15.2
Using Physical Change to Separate
Many such areas that lie close to the sea obtain drinking water by using physical properties of water to separate it from the salt.
One of these methods, which uses the property of boiling point, is a type of distillation.

55. Properties of Matter
15.2
Distillation
The process for separating substances in a mixture by evaporating a liquid and recondensing its vapor is distillation.
It usually is done in the laboratory using an apparatus similar to that shown.

56. Properties of Matter
15.2
Distillation
Two liquids having different boiling points can be separated in a similar way.
The mixture is heated slowly until it begins to boil.
Vapors of the liquid with the lowest boiling point form first and are condensed and collected. Then, the temperature is increased until the second liquid boils, condenses, and is collected.

58. Chemical Change

59. Chemical Properties and Changes
Properties of Matter
15.2
Chemical Properties and Changes
The tendency of a substance to burn, or its flammability, is an example of a chemical property because burning produces new substances during a chemical change.
A chemical property is a characteristic of a substance that indicates whether it can undergo a certain chemical change.

60. FLAMMABILITY
Flammability - A materials ability to burn in the presence of Oxygen.
Flammability

61. Reactivity
Reactivity – the property that describes how readily a substance combines chemically with another substance.
Nitrogen – Low reactivity
Oxygen – Very high reactivity
Ox. Reacts with most other elements.
Ex. O reacts with iron and water to form
______________.
Rust

62. How You recognize a Chemical Change
3 common types of Evidence for a Chemical Change.
A. Change in Color
Ex: Gold, Brass, and Silver tarnish
B. Production of a gas
Ex: Baking Soda and Vinegar
C. Formation of a precipitate
If you add lemon juice or vinegar to milk, small bits of white solid will separate from the liquid.
Its called Milk Curdling

63. Detecting Chemical Change
Properties of Matter
15.2
Detecting Chemical Change
If you leave a pan of chili cooking unattended on the stove for too long, your nose soon tells you that something is wrong.
This burnt odor is a clue telling you that a new substance has formed.

64. Properties of Matter
15.2
The Identity Changes
A change of one substance to another is a chemical change.
The foaming of an antacid tablet in a glass of water and the smell in the air after a thunderstorm are other signs of new substances being produced.
Click image to view movie

65. Properties of Matter
15.2
The Identity Changes
Clues such as heat, cooling, or the formation of bubbles or solids in a liquid are helpful indicators that a reaction is taking place.
However, the only sure proof is that a new substance is produced.
The only clue that iron has changed into a new substance is the presence of rust.
Burning and rusting are chemical changes because new substances form.

66. Using Chemical Change to Separate
Properties of Matter
15.2
Using Chemical Change to Separate
One case where you might separate substances using a chemical change is in cleaning tarnished silver.
Tarnish is a chemical reaction between silver metal and sulfur compounds in the air which results in silver sulfide.
It can be changed back into silver using a chemical reaction.

67. Using Chemical Change to Separate
Properties of Matter
15.2
Using Chemical Change to Separate
You don’t usually separate substances using chemical changes in the home.
In industry and chemical laboratories, however, this kind of separation is common. For example, many metals are separated from their ores and then purified using chemical changes.

68. Weathering—Chemical or Physical Change?
Properties of Matter
15.2
Weathering—Chemical or Physical Change?
The forces of nature continuously shape Earth’s surface. Rocks split, deep canyons are carved out, sand dunes shift, and curious limestone formations decorate caves.
Do you think these changes, often referred to as weathering, are physical or chemical?
The answer is both.

69. Properties of Matter
15.2
Physical
Large rocks can split when water seeps into small cracks, freezes, and expands.
However, the smaller pieces of newly exposed rock still have the same properties as the original sample.
This is a physical change.

70. Properties of Matter
15.2
Chemical
A chemical change produces caves and the icicle shaped rock formations that often are found in them.
Limestone dissolves in slightly acidic moisture that seeps through the ground

71. The Conservation of Mass
Properties of Matter
15.2
The Conservation of Mass
Suppose you burn a large log until nothing is left but a small pile of ashes.
At first, you might think that matter was lost during this change because the pile of ashes looks much smaller than the log did.

72. The Conservation of Mass
Properties of Matter
15.2
The Conservation of Mass
In fact, the mass of the ashes is less than that of the log.

73. The Conservation of Mass
Properties of Matter
15.2
The Conservation of Mass
However, suppose that you could collect all the oxygen in the air that was combined with the log during the burning and all the smoke and gases that escaped from the burning log and measure their masses, too.
Then you would find that no mass was lost after all.

74. The Conservation of Mass
Properties of Matter
15.2
The Conservation of Mass
Not only is NO mass lost during burning, mass is not gained or lost during any chemical change.
According to the law of conservation of mass, the mass of all substances that are present before a chemical change equals the mass of all the substances that remain after the change.

75. Which of the following is a chemical property?
Section Check
15.2
Question 1
Which of the following is a chemical property?
A. boiling point
B. density
C. flammability
D. melting point

76. Section Check
15.2
Answer
The answer is C. Flammability indicates whether a substance will undergo the chemical change of burning.

77. Section Check
15.2
Question 2
A characteristic of a material that can be observed without changing the identity of the substances that make up the material is a _______.

78. Section Check
15.2
Answer
The answer is physical property. Examples of physical properties include color, shape, and density.

79. Section Check
15.2
Question 3
What is the law of conservation of mass?

80. Section Check
15.2
Answer
According to the law of conservation of mass, the mass of all substances that are present before a chemical change equals the mass of all substances that remain after the change.

81. Mixture: Stuff Lab Activity
This activity will have you, the students, determine if some “stuff” is a(n) element, compound, or mixture. You will develop and write your own procedure and then write a conclusion based on your data.
Acceptable Materials:
Ring, Ring Stand, Filter Paper, Funnel, Magnet, Cups, Graduated Cylinder, Water, Beakers, Watch Glass, and Glass Stirring Rod