Mixtures, Compounds & Elements

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					Mixtures, Compounds & Elements




                TOPIC # 4
                  Term #1
From the Biggest Bang to the Smallest Particle
                We have just gone through a phase
                              A brief review.


• Matter as we have just learned
  can exist in four phases.
• Solids, Liquids, Gas, Plasma
• Now we need to look at the
  make-up of each phase, what
  are THEY made of?
                  Now that is class!!
                    A look at the 4 classes of matter..


• Classifying matter by
  phase is too broad and can
  be confusing.
• Water is a good example.
• We can classify matter
  based on its make-up.
• Mixtures
• Elements,
• Compounds
• Solutions
                        Mixtures
                  Don’t get caught up in the mix!


• Matter that consists of
  two or more
  substances combined
  together but not
  chemically combined.
• Examples of mixtures:
• Salad
• Granite
               Properties of Mixtures
                      what gives them away?


• Substances in a mixture
  are not chemically
  combined.
• The substances keep their
  separate identities.
• May change in physical
  appearance.
• Physical properties may
  change as well.
• Substances in a mixture
  can occur in any amount.
• Substances in a mixture
  can be separated out.
               Types of Mixtures
                   Then there was two…


• Mixtures can be class
  according to how well
  they are mixed.
• Heterogeneous
  Mixture
• Homogeneous
  Mixture
             Heterogeneous Mixture
                     Not well mixed…


• A mixture that does
  not appear to be the
  same throughout.
• Particles are large
  enough to be seen.
• Not all mixtures are
  just make of liquid.
• Can be separated
  easily.
               Homogeneous Mixture
                       best mixed mixture.
• A mixture that appears to
  be the same throughout.
• The particles are very
  small and can not be seen
  in the mixture.
• Some particles are
  suspended in the liquid.
  They are mixed but not
  dissolved.
• Known as a colloid.
• Fog & milk are good
  examples.
• These mixtures scatter
  light.
                        Solutions
                        It is not an answer!!


• A type of homogeneous
  mixture of two or more
  substances in a single
  physical state.
• “Best mixed” of all
  mixtures
• Solutions consist of two
  components.
• Solute- substance that is
  dissolved.
• Solvent- substance that
  does the dissolving.
                     Solutions cont…
                       How well do they get along?


• If a substance can be
  dissolved into another
  substance it is said to be
  soluble.
• If a substance does not
  dissolve it is said to be
  insoluble.
• Solubility is the amount
  of solute that can be
  dissolved in a given
  amount of solvent.
• An alloy is a metal
  solution.
                        Elements
                          the simplest…


• When all substances are
  alike it is known as a pure
  substance. It is the same
  throughout.
• Elements are the simplest
  pure substances in the
  universe.
• Atoms of elements are the
  same throughout the
  element.
                  Element symbols
                   a nickname for a group of purist!!


• To abbreviate elements we
  can use chemical symbols.
• Each symbol consists of
  one or two letters usually
  taken from the elements
  name.
• Carbon --- C
• Chlorine – Cl
• Calcium -- Ca
                      Compounds
                       A party for elements…


• Pure substances that are
  made up of two or more
  elements.
• Can be broken down into
  simpler substances.
• Have different properties
  than the individual
  elements.
• NaCl (Salt) (edible)
• Na soft reactive metal
  (death)
• Cl toxic green gas (death)
                 Compounds cont…
                     What are they made of..?


• Compounds are made of
  molecules, made of two or
  more atoms chemically
  combined.
• Smallest particle of a
  compound.
• All molecules of a
  compound are alike.
• H20—2 Hydrogen atoms
  and 1 oxygen atom.
                Chemical Formula
                    Lets write like a chemist!!!!


• We can put elements
  together to form
  compounds, these are
  known as chemical
  formulas.
• H2O2—Peroxide
• When we write formulas,
  we can use numbers to
  represent the amount of
  that element in a
  compound.
• This is known as a
  subscript
                 Chemical Equations
                      They exist in science too!!!


• To show chemical
  reactions occur, scientist
  write out chemical
  equations.
• Ex. How water is formed.
• H2 + O2 2H2O
• The bold number is called
  a coefficient. These
  numbers are used to
  balance an equation.
• There must be equal
  amounts of atoms or
  molecules on each side.
                        Classes dismissed!!!
                               4 classes of matter review.

•   What are the 4 classes of matter? Characterize each one.
•   What are three properties of a mixture?
•   What is the difference between a hetero & homogeneous mixture?
•   What are two parts of a solution?
•   What is a colloid?
•   What is a pure substance?
•   Write chemical symbols for oxygen, sodium, boron, gold, carbon and tungsten.
•   How is a compound different form an element
•   What is a molecule?

				
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posted:5/24/2012
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