Chapter 3 Classification of Matter by bac0A150

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									       Chapter 2
    Classification of
         Matter
                    Objectives:
Define and give examples of 3 states of matter
Distinguish between substances and mixtures
Understand what elements are
Distinguish between metals, nonmetals and
 metalloids
Define compounds and diatomic molecules
           What is Matter?
   Anything that has mass and occupies space
    (volume)
      Composed of atoms
   Exists in three states on earth
      Solid
      Liquid
      Gas
   Exists in fourth state in space
      Plasma (An electrically neutral,
       highly ionized gas state)
                  Solids
   Definite shape and volume
   Particles tightly packed in a
    lattice pattern
   Crystalline – salt, sugar,
    quartz
   Amorphous solids – no
    regular, geometric pattern
    eg. Glass, plastic, gel
             Liquids
 Definite volume
 Not a definite shape
  (Takes shape of container)
 Particles have more energy
 Particles can move freely
               Gases
 Indefinite volume
 No definite shape
 Particles have high energy
  level
 Particles move
  independently of one
  another
      Classfication Flowchart
                                   MATTER
                     yes           Can it be physically
                                                                no
                                      separated?

              MIXTURE                                PURE SUBSTANCE

no            Is the composition           yes
                   uniform?                 yes           Can it be chemically      no
                                                            decomposed?

     Heterogeneous      Homogenous
        Mixture           Mixture                Compound                 Element
      (mechanical)       (solutions)

             Colloids?                Suspensions?
        Substances and Mixtures
   Pure Substance: a particular kind of
    matter with a definite, fixed composition
       Elements (copper, gold, oxygen)
       Compounds (sugar, salt, water)
   Mixture: a blend of two or more pure
    substances
       NOT chemically combined
          Types of Mixtures
   Heterogeneous mixtures
     Visibly different parts

     Eg. Chocolate chip cookies; granite

     Two or more phases (usually)

   Homogeneous mixtures
     Different parts not visible (uniform
      throughout)
     One phase

     Eg. Sea water, air
Homogeneous Mixtures
Also known as solutions
  very small particles (0.2 –
  2.0 nm)
                                  Tyndall Effect
  no Tyndall effect (particles
  don’t scatter light)
  particles don’t settle
  Eg: rubbing alcohol, air,
   brass alloy
Colloids
  Homogeneous or heterogenous?
  Difficult to say
  medium-sized particles
   (2.0 – 1000 nm)
  Tyndall effect
  particles don’t settle
  Eg: milk
Suspensions
 large particles (>1000 nm)
 Tyndall effect
 particles settle
 Eg: fresh-squeezed
      lemonade
Heterogeneous Mixtures

Mechanical

       Several
        components
        mixed and
        visible
       Eg: Raisin Bran

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            Pure Substances
   Elements
      A substance that cannot be
       separated into simpler
       substances
   Compound
      Two or more elements
       combined through a chemical
       reaction
      Different properties than
       elements which compose it
                      Elements
   Classificiation
       Metal
       Nonmetal
       Metalloid
                     Elements
   Metals:
     Usually solid at room temp

     Good conductors of heat and
      electricity
     High luster (shiny)

     Ductile – easily pulled into wires

     Malleable – easily beaten into thin
      sheets
     High melting point; high density

     Usually don’t combine with each
      other
     Readily combine with nonmetals
                     Elements
   Nonmetals:
     Solids (C, P, S, Se, I2); Liquid
      (Br2); Gases (all others)
     Poor conductors of heat and
      electricity; no luster
     Low melting point; low density
     Will combine with each other
      (CO2)
     Will combine with metals or
      metalloids
     Some found uncombined in
      nature (noble gases)
               Elements
 Metalloids
   Have properties of
    both metals and
    nonmetals
   Some used for
    semiconductors in
    electronics
   Eg: Silicon, Germanium
               Compounds
   Two or more elements
    chemically combined
   New properties
   Definite proportions
   Can be chemically
    separated
   Molecular (covalent) or
    Ionic
              Compounds
 Molecular
   Held together with covalent bonds
   Molecule: smallest uncharged
    individual unit of a compound
   Eg. Water, carbon dioxide
                Compounds
 Ionic
     Ion: positively or negatively charged
      atom or group of atoms
       Cation – positive
       Anion – negative

     Held together by ionic bond –
      attraction between positive and
      negative charges
       Diatomic Molecules
   Always exist as 2 atoms
   7 naturally occurring
      Hydrogen, oxygen, fluorine,

      bromine, iodine, nitrogen,
      chlorine
      H2, O2, F2, Br2, I2, N2, Cl2

      Memory tool – “HOFBrINCl”

       pronounced “Hoffbrinkle”
          Chemical Formulas
 Subscript       indicates # of atoms
 present
   H2O has 2 Hydrogen atoms and 1
    Oxygen atom
   H2SO4 has 2 hydrogen atoms, 1 sulfur atom, 4 oxygen atoms

   NaOH has 1 sodium atom, 1 oxygen atom, 1 hydrogen atom
                 6 carbon atoms, 12 hydrogen atoms,
   C6H12O6 has and 6 oxygen atoms
                Separating Mixtures
    Do NOT cause chemical changes
    Heterogeneous Mixtures
           Filtration




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                Separating Mixtures
    Homogeneous Mixtures
           Distillation




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               Separating Mixtures
    Homogeneous Mixtures
           Chromatography




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                Separating Mixtures
    Homogeneous
     Mixtures
           Crystallization




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