States of Matter - Download Now PowerPoint

Document Sample
States of Matter - Download Now PowerPoint Powered By Docstoc
					States of Matter


  Physical Science
   Mrs. Armstrong
     Chapter 3     States of Matter

            Table of Contents
Section 1 Matter and Energy

Section 2 Fluids

Section 3 Behavior of Gases
   Chapter 3        Section 1 Matter and Energy

                  Objectives
• Summarize the main points of the kinetic theory
  of matter.
• Describe how temperature relates to kinetic
  energy.
• Describe four common states of matter.
• List the different changes of state, and describe
  how particles behave in each state.
• State the laws of conservation of mass and
  conservation of energy, and explain how they
  apply to changes of state.
   Chapter 3   Section 1 Matter and Energy

               Bellringer

The nine drawings below contain different
types and numbers of atoms and molecules.
From your knowledge of the different
classifications of matter, categorize the
drawings shown.
Chapter 3   Section 1 Matter and Energy

     Bellringer, continued

                        1. Identify each
                           diagram as one
                           of more of the
                           following:
                           solid, liquid,
                           gas, atoms
                           only, molecules
                           only, atoms
                           and molecules.
      Chapter 3           Section 1 Matter and Energy



                       Kinetic Theory
• Here are the main points of the kinetic theory
  of matter:

   • All matter is made of atoms and molecules that act like tiny
     particles.

   • These tiny particles are always in motion. The higher the
     temperature of the substance, the faster the particles move.

   • At the same temperature, more-massive (heavier) particles
     more slower than less-massive (lighter) particles.
Chapter 3   Section 1 Matter and Energy



    Kinetic Molecular Theory
      Chapter 3        Section 1 Matter and Energy



            Kinetic Theory, continued
• The states of matter differ physically from
  one another.

  • Particles of a solid, such as iron, are in fixed
    positions.

  • In a liquid, such as cooking oil, the particles are
    closely packed, but they can slide past each other.

  • Gas particles are in a constant state of motion
    and rarely stick together.
Chapter 3     Section 1 Matter and Energy



            States of Matter
Chapter 3   Section 1 Matter and Energy



       Solid, Liquid, and Gas
     Chapter 3        Section 1 Matter and Energy



           Kinetic Theory, continued
• Solids have a definite shape and volume.

• The structure of a solid is rigid, and the particles
  have almost no freedom to change position.

   • Crystalline solids have an orderly arrangement of
     atoms or molecules.

   • Amorphous solids are composed of atoms or
     molecules that are in no particular order.
Chapter 3   Section 1 Matter and Energy



        Properties of Solids
      Chapter 3          Section 1 Matter and Energy



            Kinetic Theory, continued
• Liquids change shape, but not volume.

   • The particles in a liquid move more rapidly than those of a
     solid—fast enough to overcome the forces of attraction
     between them.

   • The particles in a liquid can slide past each other, flowing
     freely. Liquids can take the shape of the container they are
     put into.

   • Liquids have surface tension, the force acting at the surface
     of a liquid that causes a liquid, such as water, to form
     spherical drops.
Chapter 3   Section 1 Matter and Energy



                Liquid
Chapter 3   Section 1 Matter and Energy



       Properties of Liquids
     Chapter 3     Section 1 Matter and Energy



         Kinetic Theory, continued
• Gases are free to spread in all directions.

  • The particles of a gas move fast enough to break
    away from each other.

  • The space between gas particles can change, so a
    gas expands to fill the available space.

  • A gas can also be compressed to a
    smaller volume.
Chapter 3   Section 1 Matter and Energy



                  Gas
     Chapter 3       Section 1 Matter and Energy



          Kinetic Theory, continued
• Plasma is the most common state of matter.
  • Plasma is a state of matter that starts as a gas and
    then becomes ionized.
  • Plasmas conduct electric current, while gases
    do not.
  • Natural plasmas are found in lightning and fire.
    The glow of a fluorescent light is caused by an
    artificial plasma, created by passing electric
    currents through gases.
    Chapter 3        Section 1 Matter and Energy



                   Energy’s Role
• Energy is the capacity to do work.

• Sources of energy can include:

  • electricity, candles, and batteries

  • the food you eat

  • chemical reactions that release heat
Chapter 3   Section 1 Matter and Energy



               Energy
      Chapter 3        Section 1 Matter and Energy



            Energy’s Role, continued
• According to the kinetic theory, all matter is made
  of particles that are constantly in motion.

• Because the particles are in motion, they have
  kinetic energy, or energy of motion.

• Thermal energy is the total kinetic energy of a
  substance.

   • The more kinetic energy the particles in the object
     have, the more thermal energy the object has.
    Chapter 3      Section 1 Matter and Energy



          Energy’s Role, continued
• Temperature is a measure of average kinetic
  energy.

  • Unlike total kinetic energy, temperature does not
    depend on how much of the substance you have.

  • For example, a teapot contains more tea than a
    mug does, but the temperature, or average kinetic
    energy of the particles in the tea, is the same in
    both containers.
     Chapter 3     Section 1 Matter and Energy



       Energy and Changes of State
• A change of state—the conversion of a substance
  from one physical form to another—is a
  physical change.
• The identity of a substance does not change
  during
  a change of state, but the energy of a substance
  does change.
• A transfer of energy known as heat causes the
  temperature of a substance to change, which can
  lead to a change of state.
Chapter 3     Section 1 Matter and Energy



            States of Matter
    Chapter 3       Section 1 Matter and Energy


     Energy and Changes of State,
• Some changes ofcontinued energy.
                  state require

  • Evaporation is the change of a substance from a
    liquid to a gas. Energy is needed to separate the
    particles of a liquid to form a gas.

  • Sublimation is the process by which a solid turns
    directly to a gas. Sometimes ice sublimes to form a
    gas.
Chapter 3                           Section 1 Matter and Energy


      Energy and Changes of State,                     continued


 • Energy is released in some changes of state.
    • Condensation is the change of a substance from a gas
      to a liquid. Energy is released from the gas and the
      particles slow down.
    • Energy is also released during freezing, which is the
      change of state from a liquid to a solid.

 • When a substance loses or gains energy, either
   its temperature changes or its state changes, but
   not both.
   Chapter 3        Section 1 Matter and Energy



  Conservation of Mass and Energy
• The law of conservation of mass says that
  mass cannot be created or destroyed.
  • For instance, when you burn a match, the total
    mass of the reactants (the match and oxygen) is
    the same as the total mass of the products (the
    ash, smoke, and gases).
• The law of conservation of energy states
  that
  energy cannot be created or destroyed.
  • For instance, when you drive a car, gasoline
    releases its stored energy, in the form of heat,
    used to move the car.
Chapter 3   Section 1 Matter and Energy



  Law of Conservation of Mass
Chapter 3   Section 1 Matter and Energy



 Law of Conservation of Energy
    Chapter 3        Section 2 Fluids

                   Objectives
• Describe the buoyant force and explain how it
  keeps
  objects afloat.

• Define Archimedes’ principle.

• Explain the role of density in an object’s ability to
  float.

• State and apply Pascal’s principle.

• State and apply Bernoulli’s principle.
    Chapter 3             Section 2 Fluids

                        Bellringer
Although you may not be familiar with the specific details, you
have seen buoyant forces at work. You know from experience that
certain objects float in air or in water. This is because of the force
that pushes, or buoys the object up. This force opposes the weight
of the object, which is always in the downward direction.
Examine each of the drawings shown on the next slide. Then
answer the items that follow.
     Chapter 3                 Section 2 Fluids

                Bellringer, continued




1. Is the buoyant force on the lump of gold greater than, less than, or equal
     to the gold’s weight?
2. Is the buoyant force on the balloon greater than, less than, or equal to the
     balloon’s weight?
3. Is the buoyant force on the boat greater than, less than, or equal to the
     boat’s weight?
4. Is the buoyant force on the submarine greater than, less than, or equal to
     the submarine’s weight?
     Chapter 3      Section 2 Fluids



                        Fluids
• A fluid is a nonsolid state of matter in which the
  atoms or molecules are free to move past each
  other, as in a gas or liquid.
• Fluids are able to flow because their particles can
  move past each other easily.
• The properties of fluids allow huge ships to float,
  divers to explore the ocean depths, and jumbo
  jets
  to soar across the skies.
Chapter 3   Section 2 Fluids



                 Fluid
     Chapter 3      Section 2 Fluids



                  Buoyant Force
• Buoyant force is the upward force exerted on
  an object immersed in or floating on a fluid.
• Buoyancy explains why objects float.
  • All fluids exert pressure: the amount of force
    exerted per unit area of a surface.
  • Archimedes’ principle states that the buoyant
    force on an object in a fluid is an upward force
    equal to the weight of the volume of fluid that the
    object displaces.
    Chapter 3      Section 2 Fluids



         Buoyant Force, continued
• The volume of fluid displaced by an object
  placed in a fluid will be equal to the volume of
  the part of the object submerged.

• The figure below shows how displacement
  works.
     Chapter 3       Section 2 Fluids



          Buoyant Force, continued
• An object will float or sink based on its
  density.

  • If an object is less dense than the fluid in which it
    is placed, it will float.

  • If an object is more dense than the fluid in which
    it is placed, it will sink.
Chapter 3   Section 2 Fluids



               Density
     Chapter 3     Section 2 Fluids



             Fluids and Pressure
• Fluids exert pressure evenly in all directions.

  • For example, when you pump up a bicycle tire, air
    particles are constantly pushing against each
    other and against the walls of the tire.
     Chapter 3         Section 2 Fluids



       Fluids and Pressure, continued
• Pressure can be calculated by dividing force by
  the area over which the force is exerted:
                                 force
                    pressure 
                                 area

 • The SI unit for pressure is the pascal (abbreviation: Pa),
   equal to the force of one newton exerted over an area of
   one square meter (1 N/m2).
     Chapter 3      Section 2 Fluids



                 Pascal’s Principle
• Pascal’s principle states that a fluid in
  equilibrium contained in a vessel exerts a
  pressure of equal intensity in all directions.

• Mathematically, Pascal’s principle is stated as
  p1 = p2, or pressure1 = pressure2.
Chapter 3                         Section 2 Fluids

                       Math Skills
  Pascal’s Principle A hydraulic lift, shown in the figure
    below, makes use of Pascal’s principle, to lift a 19,000
    N car. If the area of the small piston (A1) equals 10.5
    cm2 and the area of the large piston (A2) equals 400
    cm2, what force needs to be exerted on the small
    piston to lift the car?
    Chapter 3     Section 2 Fluids



           Math Skills, continued
1. List the given and unknown values.
  Given:      F2 = 19,000 N
              A1 = 10.5 cm2
              A2 = 400 cm2
  Unknown: F1

2. Write the equation for Pascal’s principle.
  According to Pascal’s principle, p1 = p2.
       F1 F2             (F2 )( A1 )
                   F1 
       A1 A2                A2
    Chapter 3        Section 2 Fluids



            Math Skills, continued
3. Insert the known values into the equation,
  and solve.

         (19,000 N)(10.5 cm2 )
    F1 
               400 cm2
    F1 = 500 N
Chapter 3                        Section 2 Fluids


            Pascal’s Principle, continued
  • Hydraulic devices are based on Pascal’s
    principle.
     • Hydraulic devices can multiply forces, as shown in
       the figure below. Because the pressure is the
       same on both sides of the enclosed fluid, a small
       force on the smaller area (at left) produces a
       much larger force on the larger area (at right).
Chapter 3                          Section 2 Fluids

                    Fluids in Motion
  • Viscosity is the resistance of a gas or liquid to
    flow.
  • Bernoulli’s principle states that as the speed
    of a moving fluid increases, the pressure of
    the moving fluid decreases.
     • Bernoulli’s principle is illustrated below: as a leaf
       passes through a drainage pipe from point 1 to
       point 2, it speeds up, and the water pressure
       decreases.
   Chapter 3      Section 3 Behavior of Gases

                 Objectives

• Explain how gases differ from solids and
  liquids.

• State and explain the following gas laws:
  Boyle’s law, Charles’s law, and Gay-Lussac’s
  law.

• Describe the relationship between gas
  pressure, temperature and volume.
     Chapter 3             Section 3 Behavior of Gases

                          Bellringer
The pressure of gas depends on how frequently the particles of gas strike
the sides of the container holding the gas. Use your experience and, after
examining each of the pairs of drawings shown below, decide whether
you think the pressure of the contained gas has increased, decreased, or
remained unchanged.

1. The gas in the cylinder of an automatic engine undergoes the change
shown below. Does the pressure of the gas
a. increase?
b. decrease?
c. remain unchanged?
     Chapter 3            Section 3 Behavior of Gases

             Bellringer, continued
2. The gas in the toy balloon expands outward, as shown below. After this
expansion, has the pressure of the gas
a. increased?
b. decreased?
c. remained unchanged?


3. The temperature of the water vapor in the pressure cooker increases.
Does the pressure of the gas
a. increase?
b. decrease?
c. remain unchanged?
    Chapter 3       Section 3 Behavior of Gases



              Properties of Gases
• Gases have unique properties. Some
  important properties of gases are listed below.
  • Gases have no definite shape or volume, and they
    expand to completely fill their container.

  • Gas particles move rapidly in all directions.

  • Gases spread out easily and mix with one another.
    Unlike solids and liquids, gases are mostly empty
    space.
     Chapter 3          Section 3 Behavior of Gases



      Properties of Gases, continued
• (some important gas properties, continued)
  • Gases have a very low density because their particles
    are so far apart. Because of this property, gases are
    used to inflate tires and balloons.
  • Gases are compressible.
  • Gases are fluids.
  • Gas molecules are in constant motion, and they
    frequently collide with one another and with the walls
    of their container.
Chapter 3                                Section 3 Behavior of Gases

          Properties of Gases, continued

  • Gases exert pressure on their containers.

     • The kinetic theory helps to explain pressure. Helium atoms in a
       balloon are constantly hitting each other and the walls of the
       balloon, as shown below.

     • Therefore, if the balloon is punctured, the gas will escape with a
       lot of force, causing the balloon to pop.
    Chapter 3      Section 3 Behavior of Gases



                    Gas Laws
• Boyle’s law states that for a fixed amount of
  gas at a constant temperature, the volume of
  the gas increases its pressure decreases.
  Likewise, the volume of a gas decreases as its
  pressure increases.

  • Boyle’s law can be expressed mathematically as:
    (pressure1)(volume1) = (pressure2)(volume2) ,
    or P1V1 = P2V2
Chapter 3   Section 3 Behavior of Gases



            Boyle’s Law
     Chapter 3      Section 3 Behavior of Gases



                    Math Skills
Boyle’s Law The gas in a balloon has a volume of
  7.5 L at 100 kPa. The balloon is released into the
  atmosphere, and the gas expands to a volume of
  11 L. Assuming a constant temperature, what is
  the pressure on the balloon at the new volume?
1. List the given and unknown values.
   Given: V1 = 7.5 L
             P1 = 100 kPa
             V2 = 11 L
   Unknown:        P2
Chapter 3                     Section 3 Behavior of Gases

                Math Skills, continued
  2. Write the equation for Boyle’s law, and
    rearrange the equation to solve for P2.
    P1V1 = P2V2
          PV1
      P2  1
           V2

  3. Insert the known values into the equation,
    and solve.
           (100 kPa)(7.5 L)
      P2 
                 11 L
      P2 = 68 kPa
Chapter 3                        Section 3 Behavior of Gases

               Gas Laws, continued
 • Charles’s law states that for a fixed amount of
   gas at a constant pressure, the volume of the
   gas increases as its temperature decreases.
   Likewise, the volume of a gas decreases as its
   temperature increases.

    • As shown below, if the gas in an inflated balloon is
      cooled (at constant pressure), the gas will decrease
      in volume and cause the balloon to deflate.
Chapter 3    Section 3 Behavior of Gases



            Charles’s Law
Chapter 3                         Section 3 Behavior of Gases


                Gas Laws, continued
  • Gay-Lussac’s law states that the pressure of a
    gas increases as the temperature increases if
    the volume of the gas does not change.

     • This is why, if a pressurized container that holds
       gas, such as a spray can, is heated, it may explode.
Chapter 3      Section 3 Behavior of Gases

            Concept Mapping
    Chapter 3      Standardized Test Prep



         Understanding Concepts
1. Which of the following changes of state is
   exothermic?

  A. evaporation
  B. freezing
  C. melting
  D. sublimation
    Chapter 3      Standardized Test Prep



         Understanding Concepts
1. Which of the following changes of state is
   exothermic?

  A. evaporation
  B. freezing
  C. melting
  D. sublimation
    Chapter 3     Standardized Test Prep


          Understanding Concepts
2. Which of these statements describes the
   particles of a liquid?

  F. Particles are far apart and move freely.
  G. Particles are close together and vibrate in
     place.
  H. Particles are far apart and unable to change
     location.
  I. Particles are close together and move past
     each other easily.
    Chapter 3     Standardized Test Prep



          Understanding Concepts
2. Which of these statements describes the
   particles of a liquid?

  F. Particles are far apart and move freely.
  G. Particles are close together and vibrate in
  place.
  H. Particles are far apart and unable to change
     location.
  I. Particles are close together and move past
  each     other easily.
    Chapter 3     Standardized Test Prep



         Understanding Concepts
3. As the plunger is depressed, the volume of a
   syringe filled with helium gas is reduced from
   25 mL to 10 mL. If the initial pressure is 150
   kPa, what is the final pressure, in kPa,
   assuming constant temperature?
    Chapter 3     Standardized Test Prep



         Understanding Concepts
3. As the plunger is depressed, the volume of a
   syringe filled with helium gas is reduced from
   25 mL to 10 mL. If the initial pressure is 150
   kPa, what is the final pressure, in kPa,
   assuming constant temperature?

Answer: 375 kPa
    Chapter 3      Standardized Test Prep


                 Reading Skills
Read the passage below. Then answer the question.

  If the temperature in a citrus orchard drops
  below
  –2°C for several hours, the fruit will freeze and
  be destroyed. Citrus growers spray tiny droplets
  of water to protect the crop if a freeze is
  predicted. Protection comes from the heat
  released as the heated water cools. However,
  much of the heat that protects trees from
  freezing is released as the water freezes.
    Chapter 3      Standardized Test Prep



                 Reading Skills
4. Based on the energy changes that occur
   when materials change state, determine how
   water freezing on the fruit can protect it from
   becoming too cold?
    Chapter 3      Standardized Test Prep



                 Reading Skills
4. Based on the energy changes that occur
   when materials change state, determine how
   water freezing on the fruit can protect it from
   becoming too cold?

Answer: The process of freezing is exothermic,
  so heat is generated as water changes from
  the liquid to the solid state. This heat protects
  the tree as the water freezes on it.
    Chapter 3    Standardized Test Prep



           Interpreting Graphics
Base your answers to questions 5 through 8 on
  the graph below.
    Chapter 3     Standardized Test Prep



           Interpreting Graphics
5. What is the boiling point of the substance
   shown on the graph?

  A. 20°C
  B. Between 20°C and 80°C
  C. 80°C
  D. Above 80°C
    Chapter 3     Standardized Test Prep



           Interpreting Graphics
5. What is the boiling point of the substance
   shown on the graph?

  A. 20°C
  B. Between 20°C and 80°C
  C. 80°C
  D. Above 80°C
    Chapter 3      Standardized Test Prep



            Interpreting Graphics
6. In what state is the substance at a
   temperature of 30°C?

  F. gas and liquid mix
  G. liquid
  H. solid
  I. solid and liquid mix
    Chapter 3      Standardized Test Prep



            Interpreting Graphics
6. In what state is the substance at a
   temperature of 30°C?

  F. gas and liquid mix
  G. liquid
  H. solid
  I. solid and liquid mix
    Chapter 3     Standardized Test Prep



           Interpreting Graphics
7. How will the substance change if energy is
   added to the liquid substance at 20°C?

  A. The liquid will freeze.
  B. The liquid will vaporize.
  C. The liquid will become warmer.
  D. The liquid will not undergo any change.
    Chapter 3     Standardized Test Prep



           Interpreting Graphics
7. How will the substance change if energy is
   added to the liquid substance at 20°C?

  A. The liquid will freeze.
  B. The liquid will vaporize.
  C. The liquid will become warmer.
  D. The liquid will not undergo any change.
    Chapter 3     Standardized Test Prep



           Interpreting Graphics
8. What occurs to the substance as energy is
   added to the liquid at 80°C?

  F. The liquid will freeze.
  G. The liquid will vaporize.
  H. The liquid will become warmer.
  I. The liquid will not undergo any change.
    Chapter 3     Standardized Test Prep



           Interpreting Graphics
8. What occurs to the substance as energy is
   added to the liquid at 80°C?

  F. The liquid will freeze.
  G. The liquid will vaporize.
  H. The liquid will become warmer.
  I. The liquid will not undergo any change.

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:49
posted:2/25/2012
language:English
pages:78