Chapter 12 Lesssons
Upcoming SlideShare
Loading in...5
×
 

Chapter 12 Lesssons

on

  • 4,056 views

 

Statistics

Views

Total Views
4,056
Views on SlideShare
4,030
Embed Views
26

Actions

Likes
1
Downloads
68
Comments
0

2 Embeds 26

http://preslersclass.wikispaces.com 23
http://www.slideshare.net 3

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

Chapter 12 Lesssons Chapter 12 Lesssons Presentation Transcript

  • Chapter 12: Changes in Matter
  • You Will Discover:
    • Ways that substances can change
    • How to describe and classify chemical reactions
    • How we can use chemistry to separate substances
    • How chemical technology improves our lives
  • Vocabulary:
    • Physical change : a change in some properties of matter without forming a different kind of matter
    • Chemical change: the changing of a substance or kind of matter into a different kind of matter with different properties
    • Combustion: the process of burning
    • Reactant: substance used in a chemical reaction
    • Product: substance made during a chemical reaction
    • Chemical equation: a formula that describes a chemical reaction
    • Polymer: a large molecule made of many smaller units connected together
    • Chemical Reaction: when one or more substances change into other substances with different chemical properties
  • Lesson 1: What are Chemical Changes?
    • Physical Changes
    • Changes in:
    • Position
    • Shape
    • Size
    • Volume
    • Phase of matter
    • Chemical Change
    • *occurs when one substance or kind of matter changes into another completely different kind of matter with different properties
  • Examples of Physical Change
  • Examples of Chemical Change
  • Evidence of Chemical Change
    • When a chemical change occurs, atoms rearrange themselves to form different kinds of matter.
    • Examples:
    • Antacid tablets - tiny bubbles of carbon dioxide gas
    • Burning Log - gives off heat and light
  • Chemical Changes and Energy Changes
    • During Chemical Changes:
    • * bonds between atoms break
    • * new bonds form
    • This involves taking in or giving off energy.
    • Example:
    • Combustion - gives off heat and light
  • Questions to Discuss
    • What is the difference between a chemical change and a physical change?
    • List three types of evidence of chemical change?
    • List three types of physical changes?
    • Look at the pictures of the copper tree on pages 376 and 377, what evidence of a chemical change do you see?
  • Lesson 2 - What are some kinds of chemical reactions?
    • During a chemical reaction , one or more substances change into other substances with different chemical and physical properties.
    • These substances are called reactants . The reactants undergo a chemical change to produce the product .
  • Chemical Equations
    • A chemical equation is a scientific sentence that shows what is happening during a chemical reaction.
    • The reactants are listed on the left side of the equation and the product is found on the right .
  • Examples of Chemical Equations
    • 2Mg + 0 2 = 2MgO
    • Reactants Product
    • *This chemical equation creates Magnesium Oxide .
  • Law of Conservation of Mass
    • Matter cannot be created or destroyed during a chemical reaction.
    • The total mass of the reactants is equal to the total mass of the product.
        • Example: If you bake a cake, the mass of the ingredients equals the mass of the cake, plus the gases that come from the oven to make the cake smell good.
  • Types of Chemical Reactions
    • Decomposition reaction - compounds split apart to form smaller compounds or elements
    • Combination reaction - elements or compounds come together to form new compounds.
    • Replacement reaction - at least one molecule splits apart and the parts of that molecule switch places.
  • Example of Decomposition Reaction
    • Electrolysis of Water
    • The water separates into Oxygen and Hydrogen atoms. This compound separates into the two different molecules .
  • Example of Combination Reaction
    • Two separate substances are put together and they create a completely different substance with different properties
  • Example of Replacement Reaction
    • In this reaction, the two compounds switch partners to form two new compounds.
  • Questions to Discuss
    • What do chemical equations show?
    • List and describe the three kinds of chemical reactions.
    • When magnesium reacts with oxygen gas a reactions occurs. What type of reaction it it? Why?
    • Using the chemical equation on page 379. If you start with 100 atoms of magnesium, how many molecules of oxygen are needed to react with all the magnesium?
  • Lesson 3 - How are chemical properties used?
    • Chemical Properties can be used:
        • Separating mixtures
        • Separating metals from ores
        • Identifying substances
  • Separating Mixtures
    • Substances may also have different chemical properties that can be used to separate them from one another.
    • Example:
        • Archaeologists use vinegar to separate fossils from limestone. The vinegar dissolves the limestone, freeing the fossil.
  • Separating Metals from Ores
    • Ores are rocks with metals combined with other substances.
    • Example:
        • Iron ore contains iron oxide. Heating iron ore in a furnace with with solid carbon allows the iron to separate from the oxygen in the ore. The result is pure iron and carbon dioxide.
    Iron ore
  • Identifying Substances
    • Scientists use chemical properties to identify substances.
    • Acids and bases are two common types of substances.
    Acid Base
  • Acids and Bases
    • Acids and Bases react with chemicals in special paper called universal indicator paper .
        • Acids turn the paper red
        • Bases turn the paper purple
    • Universal indicator paper is not enough to completely identify a substance, but helps narrow substances down.
  • Flame Test
    • Scientists use flame tests to identify a substance.
    • A material is heated in a flame, different substances will cause the flame to have different colors .
  • Questions to Discuss
    • How can chemical properties be used to separate substances in a mixture or compound?
    • What type of reaction is it when purifying iron ore? (2FeO + C = 2Fe + CO 2 )
    • How might a scientist distinguish the following compounds strontium chloride and potassium chloride?
    • What color do you think indicator paper would turn if it were dipped in shampoo? Why?
  • Lesson 4 - How is chemical technology used in our lives?
    • Chemistry and Health
    • Chemistry and New Materials
    • Chemistry and Transportation
    • Chemistry and Technology
    • Chemicals and Safety
  • Chemistry and Health
    • Alexander Fleming made an accidental discovery that led to the development of antibiotics.
        • Fleming grew bacteria in dishes. One of his dishes became contaminated with mold. The mold killed the bacteria. Fleming named this mold penicillin.
    • Chemists have also identified substances
    • that help people stay healthy. These
    • substances are called vitamins.
  • Chemistry and New Materials
    • Some materials are found in nature, like wool or cotton.
    • Scientists have invented some common materials, like nylon , plastic , and concrete .
        • Nylon is a polymer , made of six carbon atom, seven hydrogen atoms, and one nitrogen atom.
        • A polymer may have thousands or millions of units in a single chain.
    Plastic Nylon Concrete
  • Chemistry and Transportation
    • Natural rubber comes from trees . It bends easily and is waterproof .
        • It becomes brittle and
        • cracks in cold weather.
    • Scientists discovered that by
    • heating the rubber and adding
    • sulfur they made rubber durable and usable
    • year-round .
        • In the 1900s scientists developed a way to make artificial rubber.
        • It is used for tires, tennis shoes
  • Chemistry and Technology
  • Chemicals and Safety
    • Some chemicals are used to helps us clean and sanitize to keep use healthy.
    • When using chemicals it is important to:
        • Read the warning labels
        • Read the directions for use
        • Wear gloves and safety goggles
        • Open a window if necessary
        • Don’t mix any cleaners
  • Questions to Discuss
    • What are the antibiotics and how have they improved health?
    • What are three common materials that were developed by scientists?
    • How did scientists working with rubber help our modern system?
    • Why is it important to avoid mixing cleaners?
    • What is a polymer?
    • Which of the technological advances has most improved human lives?