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Matter

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					                             Matter
   States of matter
   Kinetic theory of matter: matter is composed of tiny particles that
    are constantly in motion
   -solid, liquid, gas, plasma
   Solids
         -have a definite shape and volume
         -cannot be squeezed into a smaller volume
         -particles are held close together
         -crystalline solids: solids in which the
                  particles are arranged in repeating
                  geometric patterns
         -noncrystalline solids: amorphous
                  solids, also some consider them to
                  be thick liquids because the
                  particles are not arranged like crystals
                  -glass, many plastics, some kinds of wax
                    Liquids

      -take the shape of their container
      -cannot be squeezed into a smaller
    volume
      -particles are close together but can
    move
       around each other
      -definite shape, no definite volume
      -viscosity- how thick the liquid is at a
            specific temperature
            Gases and Plasma
   Gases
       -no definite shape or volume
       -particles have enough energy to separate
        from each other
       -spread evenly in a container
   Plasma
       -most common form of matter in the universe
       -gaslike mixture of negatively and positively
        charged particles
       -mercury gas in a fluorescent light becomes
        a plasma when switched on
                     Phases
   Thermal Expansion
      -almost all matter expands as it warms and
       contracts as it cools
      -kinetic theory explains thermal expansion
   Changes in State
      -vaporization-changing a liquid to a gas
      -evaporation-liquid changes to a gas
       gradually at temperatures below the boiling
       point
        Terms applied to phases
   -boiling point- add heat until it changes to
        bubbles of gas beneath the surface


      -condensation- gas changes to a liquid when
       it is cooled below the boiling point
      -heat of fusion- the amount of energy needed
       to change a material from a solid state to a
       liquid state
              -for water=334kJ/kg
      -heat of vaporization- the amount of heat
       needed to change from a liquid to a gas
              -for water=2260kJ/kg
                    Pressure
   Pressure
      -the amount of force exerted per unit of area
      P=F/A
      Measuring pressure
            -pascal (Pa) is the SI unit of measure
            -most pressures are recorded in kPa
            -at sea level, Earth’s atmosphere exerts
             a pressure of 101.4kPa
            -at 5km above, ATM=54kPa
            -at 50km, ATM=0.15kPa
              Boyle and Charles
   Boyle’s Law
              -if you decrease the volume of a
              container of gas the pressure of the gas
              will increase, provided the temperature
              does not change.
       P1V1=P2V2
              -practice problems
       Charles’s Law
              -the volume of a gas increases with
               increasing temperature, provided the
               pressure does not change
              V1/T=V2/T2
                      -practice problems
                 More old guys
   Archimedes’ Principle: the buoyant force on an
    object in a fluid is equal to the weight of the fluid
    displaced by the object


       buoyancy-the ability of a liquid or gas to
              exert an upward force on an object
              immersed in it
   Pascal’s Principle: pressure applied to a fluid is
    transmitted unchanged throughout the fluid
             -squeezing toothpaste
                  Still more old guys
   -hydraulic lifts: Two cylinders, one small
         diameter, one large. Push the piston on the
         small one to generate a large amount of
         pressure. That pressure is transferred to
         the large one.
   Bernoulli’s Principle: as the velocity of a fluid increases, the pressure
    exerted by the fluid decreases
        -two aluminum cans, blow between
        -blow over a sheet of paper
        -airplane wing
        -back spin on a ball makes it go faster
        -Venturi effect: fluids flow faster through
                    narrow spaces (Bernoulli), this
                    increased speed lowers pressure
                    (Venturi)
                   -skyscrapers close together, windows
                    pop out on windy days
    Matter, mixtues, and solutions
   Composition of Matter
          elements= contain the same types of atoms
          compound= materials made from two or
                       more types of elements
          substance=either an element or compound
   Mixtures
   heterogeneous mixture= a mixture in which
          different materials can easily be
          distinguished
   homogeneous mixture= a mixture in which two
          or more materials are uniformly spread out
          -solution= types of homogeneous mixture,
                      usually in liquid form
                      -distillation separates parts
   colloid=a heterogeneous mixture that never
          settles, like milk
          -scatters light
                      Tyndall effect= the scattering of light
                       particles by a mixture
          Solutions continued
   suspension= a heterogeneous
    mixture containing
       a liquid in which visible particle
    settle
      precipitate=particles that settle
   Density can be used to test for
    purity.
             Settle Separate Part.size   Scat.
             ?      ?
                                         Light?
Solution     No     No        0.1-       No
                              1nm
Colloid      No     No        1-    Yes
                              100nm
Suspension
             Yes    Yes       >100nm     yes
                      Properties
   Physical property=properties you can observe without
    changing the material
   Physical change= a change in size, shape, or phase
   Chemical property= a characteristic of a substance that
    indicates whether it can undergo a certain chemical change
        reactivity=to participate actively in
                 reactions
   Chemical change= and change from one substance to
    another
   Law of Conservation of Mass/Energy
        1. Matter/energy can neither be created or
           destroyed
        2. The amount of matter/energy in the
           universe remains constant

				
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posted:7/28/2012
language:English
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