Notes on Elements_ Compounds_ and Mixtures

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					Notes on Elements, Compounds, and Mixtures

Elements---      a pure substance that can not be broken down into smaller parts
                 (ex. H, O2, Al)

Compound--- a pure substance of two or more elements that are chemically combined
            (ex. H2O, CaCO3, CO2 )

Mixture---       Two or more substances that are not chemically joined to one another
                 (ex. Vegetable soup, sugar water, brass)

    Homogeneous                   Heterogeneous
    Appear as single          Larger particles mixed in
   Can not be filtered         Can be filtered (except
                                     for colloids)
 Particles are evenly          Particles are not evenly
      distributed                     distributed
Transparent (except for            Not transparent

*** Colloid---           mixtures with tiny particles that are suspended in liquid and stay suspended, can
                         not be filtered, scatter light, cloudy
*** Suspension---        mixtures with larger particles that are suspended in the liquid but settle out over

Mixture                  Compound               Element                Mixture

How do decide what a substance is…
                                 Is it a pure substance?
                                  Are all parts the same?
                                    There can be no +.

                    YES                                          NO

           Is it an element or                                    MIXTURE
               compound?                          Is it homogeneous or heterogeneous?
           Is there more than                            Is it the same through out?
           one type of atom?                               Can you see particles?

     YES               NO

COMPOUND                    ELEMENT            HOMOGENEOUS             HETEROGENEOUS
                                                Evenly spread              Particles
                                                  Solution                 Cloudy