How to Use This Presentation

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

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

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

11. Section 1 Forming New Substances Chapter L2 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. Section 1 Forming New Substances Chapter L2

13. Section 1 Forming New Substances Chapter L2 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. Section 2 Chemical Formulas and Equations Chapter L2 Bellringer Start up your computers Open your books and read pg. 32-37 This will take you less than 10 min. When you are done, go to kahoot.it on your computer.

15. Section 2 Chemical Formulas and Equations Chapter L2 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. Section 2 Chemical Formulas and Equations Chapter L2 Bellringer Write the following chemical formulas in yourscience 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. Section 2 Chemical Formulas and Equations Chapter L2 Bellringer Start up your computers. Go to Kahoot.it Log in using the PIN: 672155 Use your first name as your nickname

18. Section 2 Chemical Formulas and Equations Chapter L2 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. Section 2 Chemical Formulas and Equations Chapter L2 Chemical Formulas • Achemical formulais 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. Section 2 Chemical Formulas and Equations Chapter L2 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. Section 2 Chemical Formulas and Equations Chapter L2 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.

22. Section 2 Chemical Formulas and Equations Chapter L2 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. Section 2 Chemical Formulas and Equations Chapter L2

24. Section 2 Chemical Formulas and Equations Chapter L2 Chemical Equations • Describing Reactions by Using Equations • Achemical equationuses chemical symbols and formulas as a shortcut to describe a chemical reaction. • From Reactants to Products • The starting materials in a reaction arereactants. • The substances formed from a reaction areproducts.

25. Section 2 Chemical Formulas and Equations Chapter L2

26. Section 2 Chemical Formulas and Equations Chapter L2 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. Section 2 Chemical Formulas and Equations Chapter L2 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. Section 2 Chemical Formulas and Equations Chapter L2 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. Section 2 Chemical Formulas and Equations Chapter L2 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. Section 2 Chemical Formulas and Equations Chapter L2

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

32. Section 3 Types of Chemical Reactions Chapter L2 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 yourscience journal.

33. Section 3 Types of Chemical Reactions Chapter L2 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: https://www.quia.com/ba/22228.html

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

35. Section 3 Types of Chemical Reactions Chapter L2 Synthesis Reactions • Asynthesis reactionis 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. Section 3 Types of Chemical Reactions Chapter L2 Decomposition Reactions • Adecomposition reactionis a reaction in which a single compound breaks down to form two or more simpler substances. • Decomposition is the reverse of synthesis.

37. Section 3 Types of Chemical Reactions Chapter L2 Single-Displacement Reactions • Asingle-displacement reactionis 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 ElementsIn a single-displacement reaction, a more reactive element can displace a less reactive element in a compound.

38. Section 3 Types of Chemical Reactions Chapter L2 Double-Displacement Reactions • Adouble-displacement reactionis 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. Section 3 Types of Chemical Reactions Chapter L2

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

42. Section 3 Types of Chemical Reactions Chapter L2

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

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

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

49. Section 4 Energy and Rates of Chemical Reactions Chapter L2 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. Section 4 Energy and Rates of Chemical Reactions Chapter L2 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.