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					           Chapter 3 Matter

               •Mixtures
              •Substances
   •Chemical And Physical properties
•Law of conservation of mass/proportions
              All Matter

Can it be separated by physical means?
               •Cutting
                •sorting
       Yes      •slicing      No
       Mixture           Pure substance
                 Mixture


         Is the composition uniform?
          Yes                No


Homogenous Mixtures Heterogeneous mixtures
Homogenous Mixtures Heterogeneous mixtures
    (Uniform properties)    (Non-uniform properties)

   •Brine (salt water)       •Soil
                             •Wood
   •All solutions
                             •Granite
   •sugar and water          •Blood
   •air                      •Veggie soup
   •stainless steel          •Notebook
   •CuSO4                    •textbook
   •Alloys (Brass,bronze)    •Milk
         Pure Substances


Can it be decomposed by chemical means?

  Yes                      No

Compounds                   Elements
  Compounds               Elements
•Water
                          •Hydrogen
•Quartz
                          •Silver
•Sodium chloride (NaCl)
                          •Gold
•Barium nitride (Ba3N2)
                          •Mercury
•Magnesium Sulfate
                          •Tin
(Epson’s salts) MgSO4
                          •Radon
                          •Neon
           Homogenous Mixtures


          A solution has two parts:
          Solute and a solvent

                                 Sugar and water
Water=
solvent
                                      Sugar particles
                                         (yellow)
          Changes in Properties
        Two types Chemical and Physical
Chemical Changes: a new substance appears.

Example: rot, rust, decay, ferment, oxidize, burn,
Digestion, react with

            Forms of detection:
               Gas production
                Color change
               energy change
 a precipitate forms (a gel like substance)
               Physical Change:
    Changes its look or physical appearance.

Examples: Cut, chop, tear, melt, bend, fold,
      dissolve, pull, pound, freeze

     Molecules and atoms remain unchanged

              Physical properties
What does it look like...size, shape, length, density,
          mass, odor, taste, malleability
        Extensive and Intensive
              Properties

   Extensive; depend on amount of
  matter present. For example; mass
  volume and length.
 Intensive Properties; does not
  depend on amount of matter present.
  For example; melting point, crystalline
  shape, refractive index, color, boiling
  point, density,and conductivity.
    Chemical properties

     How does it react.
        Flammable,
   Flash point, Half-life,
oxidation rate, reduction rate,
    Reactivity, Stability
       States of Matter

 Solids:Rigid, definite volume &
  shape. Limited molecule motion.
 Liquids, distinct volume, flows,
  random molecule motion
 Gases, No fixed shape or volume,
  Very compressible, flows. Very
  high random motion.
           Exothermic Process
           (energy is given off)

         Freeze        condensation

solids             liquids                gas



         Melting             vapor/boil
           Endothermic process
           (energy is required)
Energy Change   Process       Example

Energy in       Breaking bonds H2  H + H
(Endothermic)
Energy out      Forming bonds O2 +2 H2  2H2O
(Exothermic)
 Law of Definite Proportions
    Regardless of the amount, a compound is
     always composed of the same elements in
     the same proportion by mass.


Percent by mass(%) = mass of element
                   mass of compound * 100%
Law of Multiple Proportions p. 76
   When different compounds are formed by a
    combination of the same elements, different
    masses of one element combine with the
    same relative mass of the other element in a
    ratio of small whole numbers.

     Ex. PbO and PbO2
    Or N2O, NO, NO2 , and N2O3
   Read about distillation,Separation etc.

				
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posted:5/10/2013
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