1. How to Use This Presentation
To View the presentation as a slideshow with effects
select “View” on the menu bar and click on “Slide Show.”
To advance through the presentation, click the right-arrow key or the space bar.
From the resources slide, click on any resource to see a presentation for that resource.
From the Chapter menu screen click on any lesson to go directly to that lesson’s presentation.
You may exit the slide show at any time by pressing the Esc key.

2. Standardized Test Prep Image and Math Focus Bank
Resources
Chapter Presentation
Bellringers
Transparencies
Standardized Test Prep
Image and Math Focus Bank
Visual Concepts

3. Chapter L2 Table of Contents Section 1 Forming New Substances
Chemical Reactions
Table of Contents
Section 1 Forming New Substances
Section 2 Chemical Formulas and Equations
Section 3 Types of Chemical Reactions
Section 4 Energy and Rates of Chemical Reactions

4. Chapter L2 Bonds: Holding Molecules Together, continued
Section 1 Forming New Substances
Bonds: Holding Molecules Together, continued
Send one member of your group back to pick up a “bowl” of marshmallows and a box of toothpicks.
Work with your group to create a model of Hydrogen Peroxide
H2O2 – Each group member needs to make their own model.

5. Chapter L2 Bonds: Holding Molecules Together, continued
Section 1 Forming New Substances
Bonds: Holding Molecules Together, continued
Once your group has 2 or 4 hydrogen peroxide models, use the models to create as many water molecules and oxygen molecules as possible.
Water H2O
Oxygen O2

6. Chapter L2
Section 1 Forming New Substances
Bellringer
What do baking bread, launching the space shuttle, and digesting food have in common?
Write your answer in your science journal.

7. Chapter L2 Bellringer Locate your directed reading from yesterday.
Section 1 Forming New Substances
Bellringer
Locate your directed reading from yesterday.
Work to complete this independently.
If you are done, please find your free reading book and free read. (If you are in need, please help yourself to a book from my library)

8. Chapter L2
Section 1 Forming New Substances
Objectives
Describe how chemical reactions produce new substances that have different chemical and physical properties.
Identify four signs that indicate that a chemical reaction might be taking place.
Explain what happens to chemical bonds during a chemical reaction.

9. Chapter L2 Chemical Reactions
Section 1 Forming New Substances
Chemical Reactions
A chemical reaction is a process in which one or more substances change to make one or more new substances.
The chemical and physical properties are different than the original substances.

10. Chemical Reactions, continued
Chapter L2
Section 1 Forming New Substances
Chemical Reactions, continued
Signs of Chemical Reactions
color changes,
gas formation,
the formation of a precipitate (a solid substance formed in a solution),
energy given off as light, thermal (heat) energy, or electrical energy.
A Change of Properties The most important sign of a chemical reaction is the formation of new substances that have different properties.

11. Bonds: Holding Molecules Together
Chapter L2
Section 1 Forming New Substances
Bonds: Holding Molecules Together
A chemical bond is an attraction that holds atoms together in a molecule.
(We Know This Mr. Krohn! We studied it for 3 weeks!)
Breaking and Making Bonds (3 step process)
If molecules bump into each other with enough energy, the chemical bonds in the molecules break.
The atoms then rearrange,
new bonds form to make new substances.

12. Chapter L2
Section 1 Forming New Substances

13. Chapter L2 Bonds: Holding Molecules Together, continued
Section 1 Forming New Substances
Bonds: Holding Molecules Together, continued
New Bonds, New Substances
Whenever new substances form, their properties differ from the properties of the starting substances.
(Did we write this already?)
For example,
sodium is a violently reactive metal
chlorine is a greenish poisonous gas
The two elements combine to form a white solid called sodium chloride, or table salt.

14. Chapter L2 Bellringer Start up your computers
Section 2 Chemical Formulas and Equations
Bellringer
Start up your computers
Open your books and read pg
This will take you less than 10 min.
When you are done, go to kahoot.it on your computer.

15. Chapter L2
Section 2 Chemical Formulas and Equations
Bellringer
Copy the following questions in your science notebook:
1. Have you ever combined 2 things that had a surprising result?
2. How do changes in matter affect life on earth?
3. What are some useful chemical reactions?
*Answer each of these questions and prepare to share with a partner.

16. Chapter L2
Section 2 Chemical Formulas and Equations
Bellringer
Write the following chemical formulas in your science journal. Then, try to write the names and amount of the elements matching the symbols.
MgO H2O2 Ca3N2 Al2O3
Copy and balance the following chemical equation
____ P4 + ____ O2  ____ P2O3

17. Chapter L2 Bellringer Start up your computers. Go to Kahoot.it
Section 2 Chemical Formulas and Equations
Bellringer
Start up your computers.
Go to Kahoot.it
Log in using the PIN:
Use your first name as your nickname

18. Chapter L2 Objectives Interpret and write simple chemical formulas.
Section 2 Chemical Formulas and Equations
Objectives
Interpret and write simple chemical formulas.
Write and balance simple chemical equations.
Explain how a balanced equation shows the law of conservation of mass.

19. Chapter L2 Chemical Formulas
Section 2 Chemical Formulas and Equations
Chemical Formulas
A chemical formula is a combination of chemical symbols and numbers to represent a substance.
A chemical formula shows how many atoms of each kind are present in a molecule.

20. Chapter L2 Chemical Formula Click below to watch the Visual Concept.
Section 2 Chemical Formulas and Equations
Chemical Formula
Click below to watch the Visual Concept.
You may stop the video at any time by pressing the Esc key.
Visual Concept

21. Chemical Formulas, continued
Chapter L2
Section 2 Chemical Formulas and Equations
Chemical Formulas, continued
Writing Formulas for Covalent Compounds
You can use the name of a covalent compound to write its chemical formula.
The names of covalent compounds use prefixes.
Each prefix represents a number, as shown below.
mono- 1
hexa- 6
di- 2
hepta- 7
tri- 3
octa- 8
tetra- 4
nona- 9
penta- 5
deca- 10

22. Chemical Formulas, continued
Chapter L2
Section 2 Chemical Formulas and Equations
Chemical Formulas, continued
Writing Formulas for Ionic Compounds
To write the formula for an ionic compound, make sure the compound’s charge is 0.
The formula must have subscripts that cause the charges of the ions to cancel out.

23. Chapter L2
Section 2 Chemical Formulas and Equations

24. Chapter L2 Chemical Equations Describing Reactions by Using Equations
Section 2 Chemical Formulas and Equations
Chemical Equations
Describing Reactions by Using Equations
A chemical equation uses chemical symbols and formulas as a shortcut to describe a chemical reaction.
From Reactants to Products
The starting materials in a reaction are reactants.
The substances formed from a reaction are products.

25. Chapter L2
Section 2 Chemical Formulas and Equations

26. Chemical Equations, continued
Chapter L2
Section 2 Chemical Formulas and Equations
Chemical Equations, continued
The Importance of Accuracy
The symbol or formula for each substance in a chemical equation must be written correctly or it will not correctly describe the reaction. Some formulas and symbols can be confused.

27. Chemical Equations, continued
Chapter L2
Section 2 Chemical Formulas and Equations
Chemical Equations, continued
The Reason Equations Must Be Balanced
Atoms are never lost or gained in a chemical reaction, they are just rearranged.
Every atom in the reactants becomes part of the products.
(When writing a chemical equation, make sure the number of atoms of each element in the reactants equals the number of atoms of those same elements in the products.)
(This is called balancing the equation.)

28. Chemical Equations, continued
Chapter L2
Section 2 Chemical Formulas and Equations
Chemical Equations, continued
In the 1700s, French chemist Antoine Lavoisier found that the total mass of the reactants was always the same as the total mass of the products.
Lavoisier’s work led to the law of conservation of mass, which states that mass is neither created nor destroyed in ordinary chemical reactions and physical changes.

29. Chemical Equations, continued
Chapter L2
Section 2 Chemical Formulas and Equations
Chemical Equations, continued
How to Balance an Equation
To balance an equation, you must use coefficients.
A coefficient is a number that is placed in front of a chemical symbol or formula.
For an equation to be balanced, all atoms must be counted.
So, you multiply the subscript of each element in a formula by the formula’s coefficient.

30. Chapter L2
Section 2 Chemical Formulas and Equations

31. Chapter L2
Section 3 Types of Chemical Reactions
Bellringer
Copy down the following equation in your notebook.
__Cu + __AgNO3 __Ag+ __Cu(NO3)2

32. Chapter L2
Section 3 Types of Chemical Reactions
Bellringer
Are the products of a reaction always more complex than the reactants? Could products be simpler than the reactants? Explain your answers.
Write your responses in your science journal.

33. Chapter L2 Bellringer Start up your computer and go to kahoot.it
Section 3 Types of Chemical Reactions
Bellringer
Start up your computer and go to kahoot.it
In your agendas write down, “Chapter 2 quizzes”
Chemical Reactions
Chemical Formulas and Equations
Types of Reactions
Work on your Chemical Reaction Equations activity sheet from yesterday. If you are done, go to the following website:

34. Chapter L2 Objectives Describe four types of chemical reactions.
Section 3 Types of Chemical Reactions
Objectives
Describe four types of chemical reactions.
Classify a chemical equation as one of four types of chemical reactions.

35. Chapter L2 Synthesis Reactions
Section 3 Types of Chemical Reactions
Synthesis Reactions
A synthesis reaction is a reaction in which two or more substances combine to form one new compound.
For example, a synthesis reaction takes place when sodium reacts with chlorine to produce sodium chloride, which you know as table salt.

36. Decomposition Reactions
Chapter L2
Section 3 Types of Chemical Reactions
Decomposition Reactions
A decomposition reaction is a reaction in which a single compound breaks down to form two or more simpler substances.
Decomposition is the reverse of synthesis.

37. Single-Displacement Reactions
Chapter L2
Section 3 Types of Chemical Reactions
Single-Displacement Reactions
A single-displacement reaction is a reaction in which an element replaces another element that is part of a compound. The products of single-displacement reactions are a new compound and a different element.
Reactivity of Elements In a single-displacement reaction, a more reactive element can displace a less reactive element in a compound.

38. Double-Displacement Reactions
Chapter L2
Section 3 Types of Chemical Reactions
Double-Displacement Reactions
A double-displacement reaction is a reaction in which ions from two compounds exchange places. One of the products of this type of reaction is often a gas or a precipitate.
The next slide shows models of each of the four types of chemical reactions.

39. Chapter L2
Section 3 Types of Chemical Reactions

40. Chapter L2
Section 4 Energy and Rates of Chemical Reactions
Bellringer
On your desk you will find a list of missing quizzes for this class. Please use the first half of class to complete any and all available quizzes.
If you are done with all quizzes, please continue your work your balancing chemical equations worksheet.
If you are done with that, please turn it in to Mr. Krohn

41. Chapter L2 Bellringer What are the 4 types of reactions?
Section 4 Energy and Rates of Chemical Reactions
Bellringer
What are the 4 types of reactions?
Write your answer in your science journal.

42. Chapter L2
Section 3 Types of Chemical Reactions

43. Chapter L2 Review What is this? Ag(NO3) 3Ag(NO3) 3Ag(NO3)2
Section 3 Types of Chemical Reactions
Review
What is this?
Ag(NO3)
3Ag(NO3)
3Ag(NO3)2

44. Chapter L2 Review What is this called? __Cu + __AgNO3 __Ag+ __Cu(NO3)2
Section 3 Types of Chemical Reactions
Review
What is this called?
__Cu + __AgNO3 __Ag+ __Cu(NO3)2

45. Chapter L2
Section 4 Energy and Rates of Chemical Reactions
Bellringer
Locate your directed reading from Tuesday. Finish answering any questions that still need to be answered. We will check it and use it to assist us with notes today.

46. Chapter L2 Bellringer Start up your computers and go to Kahoot.it
Section 4 Energy and Rates of Chemical Reactions
Bellringer
Start up your computers and go to Kahoot.it
Review your notes, reread chapter 2 or free read for the first 10 minutes.
Test is Monday

47. Chapter L2 Bellringer Start up your computers and go to Kahoot.it
Section 4 Energy and Rates of Chemical Reactions
Bellringer
Start up your computers and go to Kahoot.it
Review your notes, reread chapter 2 or free read for the first 10 minutes.
Test is Monday

48. Chapter L2 Objectives Compare exothermic and endothermic reactions.
Section 4 Energy and Rates of Chemical Reactions
Objectives
Compare exothermic and endothermic reactions.
Explain activation energy.
Interpret an energy diagram.
Describe five factors that affect the rate of a reaction.

49. Chapter L2 Reactions and Energy
Section 4 Energy and Rates of Chemical Reactions
Reactions and Energy
By comparing the chemical energy of the reactants with the chemical energy of the products, you can decide if energy is released or absorbed in the reaction.
Exothermic Reactions
reactions in which energy is released.
Energy can be released as light, electrical energy, or thermal energy.

50. Reactions and Energy, continued
Chapter L2
Section 4 Energy and Rates of Chemical Reactions
Reactions and Energy, continued
Endothermic Reactions
are reactions in which energy is taken in.
The Law of Conservation of Energy
states that energy cannot be created or destroyed. The energy released in exothermic reactions was first stored in the chemical bonds of the reactants.
And the energy taken in during endothermic reactions is stored in the products.

51. Chapter L2 Rates of Reactions
Section 4 Energy and Rates of Chemical Reactions
Rates of Reactions
The speed at which new particles form is called the
rate of a reaction.
Activation Energy
is the smallest amount of energy that molecules need to react.
A chemical reaction needs a boost of energy greater than or equal to the activation energy before the reaction can start.

52. Rates of Reactions, continued
Chapter L2
Section 4 Energy and Rates of Chemical Reactions
Rates of Reactions, continued
Sources of Activation Energy
Friction is one source of activation energy. In a match, friction provides the energy needed to break the bonds in the reactants and allow new bonds to form.
An electric spark in a car’s engine is another source of activation energy. This spark begins the burning of gasoline.
Light can also be a source of activation energy for a reaction.

53. Activation Energy and Chemical Reactions
Chapter L2
Section 4 Energy and Rates of Chemical Reactions
Activation Energy and Chemical Reactions
Click below to watch the Visual Concept.
You may stop the video at any time by pressing the Esc key.
Visual Concept

54. Factors Affecting Rates of Reactions
Chapter L2
Section 4 Energy and Rates of Chemical Reactions
Factors Affecting Rates of Reactions
Temperature A higher temperature causes a
faster rate of reaction. At high temperatures, particles of reactants move quickly and collide hard and often.
At low temperatures, particles move slowly and collide less often.

55. Chapter L2 Factors Affecting Rates of Reactions, continued
Section 4 Energy and Rates of Chemical Reactions
Factors Affecting Rates of Reactions, continued
Concentration In general, a high concentration of reactants causes a fast rate of reaction.
Concentration is a
measure of the amount of one substance when it is dissolved in another substance.
When concentration is high, there are many reactant particles in a given volume.
So, there is little distance between particles and the particles collide more often and react faster.

56. Chapter L2 Factors Affecting Rates of Reactions, continued
Section 4 Energy and Rates of Chemical Reactions
Factors Affecting Rates of Reactions, continued
Surface Area is the amount of exposed surface of a substance.
Increasing the surface area of solid reactants…
increases the rate of a reaction.
Inhibitors are substances that slow down or stop a chemical reaction.
The rate of a reaction decreases in the presence of an inhibitor.

57. Chapter L2 Factors Affecting Rates of Reactions, continued
Section 4 Energy and Rates of Chemical Reactions
Factors Affecting Rates of Reactions, continued
Catalysts are substances that
speed up a reaction without being permanently changed. Because it is not changed, a catalyst is not a reactant.
A catalyst lowers the activation energy of a reaction, which allows the reaction to happen more quickly.
Catalysts called enzymes speed up most reactions in your body.

58. Chapter L2
Chemical Reactions
Concept Map
Use the terms below to complete the concept map on the next slide.
products
reactants
chemical equations
coefficients
chemical reactions
chemical formulas

59. Chapter L2
Chemical Reactions

60. Chapter L2
Chemical Reactions

61. End of Chapter L2 Show

62. Standardized Test Preparation
Chapter L2
Reading
Read each of the passages. Then answer the questions that follow each passage.

63. Standardized Test Preparation
Chapter L2
Passage 1 The key to an air bag’s success during a crash is the speed at which it inflates. Inside the bag is a gas generator that contains the compounds sodium azide, potassium nitrate, and silicon dioxide. At the moment of a crash, an electronic sensor in the car detects the sudden change in speed. The sensor sends a small electric current to the gas generator.
Continued on the next slide

64. Standardized Test Preparation
Chapter L2
Passage 1, continued This electric current provides the activation energy for the chemicals in the gas generator. The rate at which the reaction happens is very fast. In 1/25 of a second, the gas formed in the reaction inflates the bag. The air bag fills upward and outward. By filling the space between a person and the car’s dashboard, the air bag protects him or her from getting hurt.

65. Chapter L2 1. Which of the following events happens first?
Standardized Test Preparation
Chapter L2
1. Which of the following events happens first?
A The sensor sends an electric current to the gas generator.
B The air bag inflates.
C The air bag fills the space between the person and the dashboard.
D The sensor detects a change in speed.

66. Chapter L2 1. Which of the following events happens first?
Standardized Test Preparation
Chapter L2
1. Which of the following events happens first?
A The sensor sends an electric current to the gas generator.
B The air bag inflates.
C The air bag fills the space between the person and the dashboard.
D The sensor detects a change in speed.

67. Standardized Test Preparation
Chapter L2
2. What provides the activation energy for the reaction to occur?
F the speed of the car
G the inflation of the air bag
H the hot engine
I the electric current from the sensor

68. Standardized Test Preparation
Chapter L2
2. What provides the activation energy for the reaction to occur?
F the speed of the car
G the inflation of the air bag
H the hot engine
I the electric current from the sensor

69. Chapter L2 3. What is the purpose of this passage?
Standardized Test Preparation
Chapter L2
3. What is the purpose of this passage?
A to convince the reader to wear a seat belt
B to describe the series of events that inflate an air bag
C to explain why air bags are an important safety feature in cars
D to show how chemical reactions protect pedestrians

70. Chapter L2 3. What is the purpose of this passage?
Standardized Test Preparation
Chapter L2
3. What is the purpose of this passage?
A to convince the reader to wear a seat belt
B to describe the series of events that inflate an air bag
C to explain why air bags are an important safety feature in cars
D to show how chemical reactions protect pedestrians

71. Standardized Test Preparation
Chapter L2
Passage 2 An important tool in fighting forest fires is a slimy, red goop. This mixture of powder and water is a very powerful fire retardant. The burning of trees, grass, and brush is an exothermic reaction. The fire retardant slows or stops this self-feeding reaction by increasing the activation energy for the materials to which it sticks.
Continued on the next slide

72. Standardized Test Preparation
Chapter L2
Passage 2, continued A plane can carry between 4,500 and 11,000 L of the goop. The plane then drops it all in front of the raging flames of a forest fire when the pilot presses the button. Firefighters on the ground can gain valuable time when a fire is slowed with a fire retardant. This extra time allows the ground team to create a fire line that will finally stop the fire.

73. Standardized Test Preparation
Chapter L2
1. Which of the following sentences best summarizes the passage?
A The burning of forests and other brush is an exothermic reaction.
B Dropping fire retardants ahead of a flame can help firefighters on the ground stop a fire.
C Firefighters on the ground create a fire line that will help stop the fire from spreading.
D The slimy, red goop used as a fire retardant is made of a mixture of powder and water.

74. Standardized Test Preparation
Chapter L2
1. Which of the following sentences best summarizes the passage?
A The burning of forests and other brush is an exothermic reaction.
B Dropping fire retardants ahead of a flame can help firefighters on the ground stop a fire.
C Firefighters on the ground create a fire line that will help stop the fire from spreading.
D The slimy, red goop used as a fire retardant is made of a mixture of powder and water.

75. Standardized Test Preparation
Chapter L2
2. Based on the passage, which of the following statements is a fact?
F Fire retardants are always successful in putting out fires.
G No more than 4,500 L of red goop are loaded onto a plane.
H A fire retardant works by increasing the activation energy for the materials that it sticks on.
I The burning of trees is an endothermic reaction.

76. Standardized Test Preparation
Chapter L2
2. Based on the passage, which of the following statements is a fact?
F Fire retardants are always successful in putting out fires.
G No more than 4,500 L of red goop are loaded onto a plane.
H A fire retardant works by increasing the activation energy for the materials that it sticks on.
I The burning of trees is an endothermic reaction.

77. Interpreting Graphics
Standardized Test Preparation
Chapter L2
Interpreting Graphics
Use the energy diagram below to answer the questions that follow.

78. Chapter L2 1. Which letter represents the energy of the products? A A
Standardized Test Preparation
Chapter L2
1. Which letter represents the energy of the products?
A A
B B
C C
D D

79. Chapter L2 1. Which letter represents the energy of the products? A A
Standardized Test Preparation
Chapter L2
1. Which letter represents the energy of the products?
A A
B B
C C
D D

80. Standardized Test Preparation
Chapter L2
2. Which letter represents the activation energy of the reaction?
F A
G B
H C
I D

81. Standardized Test Preparation
Chapter L2
2. Which letter represents the activation energy of the reaction?
F A
G B
H C
I D

82. Standardized Test Preparation
Chapter L2
3. Which of the following statements best describes the reaction represented by the graph?
A The reaction is endothermic because the energy of the products is greater than the energy of the reactants.
B The reaction is endothermic because the energy of the reactants is greater than the energy of the products.
C The reaction is exothermic because the energy of the products is greater than the energy of the reactants.
D The reaction is exothermic because the energy of the reactants is greater than the energy of the products.

83. Standardized Test Preparation
Chapter L2
3. Which of the following statements best describes the reaction represented by the graph?
A The reaction is endothermic because the energy of the products is greater than the energy of the reactants.
B The reaction is endothermic because the energy of the reactants is greater than the energy of the products.
C The reaction is exothermic because the energy of the products is greater than the energy of the reactants.
D The reaction is exothermic because the energy of the reactants is greater than the energy of the products.

84. Chapter L2 Math Read each question and choose the best answer.
Standardized Test Preparation
Chapter L2
Math
Read each question and choose the best answer.

85. Standardized Test Preparation
Chapter L2
1. Nina has 15 pens in her backpack. She has 3 red pens, 10 black pens, and 2 blue pens. If Ben selects a pen to borrow at random, what is the probability that the pen selected is red?
A 2/15
B 1/5
C 1/3
D 2/3

86. Standardized Test Preparation
Chapter L2
1. Nina has 15 pens in her backpack. She has 3 red pens, 10 black pens, and 2 blue pens. If Ben selects a pen to borrow at random, what is the probability that the pen selected is red?
A 2/15
B 1/5
C 1/3
D 2/3

87. Standardized Test Preparation
Chapter L2
2. How many atoms of nitrogen, N, are in the formula for calcium nitrate, Ca(NO3)2?
F 3
G 2
H 6
I 1

88. Standardized Test Preparation
Chapter L2
2. How many atoms of nitrogen, N, are in the formula for calcium nitrate, Ca(NO3)2?
F 3
G 2
H 6
I 1

89. Standardized Test Preparation
Chapter L2
3. Which letter best represents the number 2 3/5 on the number line?
A P
B Q
C R
D S 3 2 1 S R Q P

90. Standardized Test Preparation
Chapter L2
3. Which letter best represents the number 2 3/5 on the number line?
A P
B Q
C R
D S 3 2 1 S R Q P

91. Standardized Test Preparation
Chapter L2
4. According to the following chemical equation, how many reactants are needed to form water and carbon dioxide?
H2CO3  H2O + CO2
F one
G two
H three
I four

92. Standardized Test Preparation
Chapter L2
4. According to the following chemical equation, how many reactants are needed to form water and carbon dioxide?
H2CO3  H2O + CO2
F one
G two
H three
I four

93. Chapter L2
Section 2 Chemical Formulas and Equations

94. Chapter L2
Section 2 Chemical Formulas and Equations