Chapter 12 Lesssons
Upcoming SlideShare
Loading in...5

Chapter 12 Lesssons






Total Views
Views on SlideShare
Embed Views



2 Embeds 26 23 3


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.

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
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?