Classification of Matter

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Classification of Matter
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Two Classifications of Matter

• Pure Substance
• Mixture

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Pure Substance

• A pure substance has the same composition
  throughout and does not vary from sample to
  sample.

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Classification of Pure Substances

• Elements
• Compounds

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Elements

• Elements are the basic building blocks of matter
• They can not be decomposed by a chemical change
• Each element has a unique set of chemical and
  physical properties
• All elements are composed of atoms ( the basic
  unit of matter)
• Elements are represented by symbols- the 1st
  letter is always capitalized and the last letter
  is lower case (ex. Na)

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Examples
Sodium
Chlorine

• Properties of Cl
• Gas
• Yellow
• Poisonous

• Properties of Na
• Solid
• Grey metal
• Reacts violently with
• water

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Lets explore more elements and their properties
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Compounds

• Compounds are composed of two or more elements.
• Elements in a compound have had their physical
  and chemical properties altered as a result of
  being chemically bonded via a chemical reaction.
• Compounds can be decomposed into two or more
  simpler compounds or elements by a chemical
  change.

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Compounds are represented by

• Chemical Formulas which use element symbols and
  subscripts to show which elements and how many
  are in the compound.
• Ex. NaCl, MgCl2

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Examples

• 2Na Cl2 ? 2NaCl

• Properties of NaCl
• Solid
• White
• Does not react with water.

Sodium Chloride
Notice how the unique properties of
the elements in the compound have been changed.
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Mixtures

• A mixture contains more than one substance.
• The composition of a mixture can vary from
  sample to sample however, each component of a
  mixture retains its own unique physical and
  chemical properties.
• Mixtures can be separated by physical means.

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Classification of Mixtures

• Homogeneous
• Heterogeneous

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Homogeneous Mixtures

• Homogeneous mixtures are also known as solutions.
• They have a uniform composition and the
  components can not be seen as separate.

Lemonade
Vinegar
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Heterogeneous Mixtures

• Heterogeneous mixtures do not have a uniform
  composition and the components can be seen as
  separate.

Granite
Pizza
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Separation Techniques

• Filtration
• Distillation
• Crystallization
• Chromatography

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Filtrations

• Used to separate heterogeneous mixtures.
• The mixture is poured through a piece of paper
  which allows the liquid part to pass and catches
  the solid portion.

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Distillations

• Used to separate homogeneous mixtures.
• This technique takes advantage of different
  boiling points.

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Crystallization

• Used to separate homogeneous mixtures.
• The liquid portion is allowed to evaporate and
  the solid portion remains behind as a crystal.

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Chromotography

• Separation occurs by allowing a mixture to flow
  along a stationary substance (usually
  chromotography paper).