UNIT III Lesson 2

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UNIT III Lesson 2

• Classification of Matter

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Classification of matter
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Some definitions to know

• A system a part of the ________ being studied in
  a given situation.
• A phase part of a _______ which is uniform in
  both composition and properties.
• Phases in a particular system are
  distinct____________ separated from each other by
  _______________ ( sometimes we use a microscope
  to see these boundaries).

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III.3 CLASSIFICATION OF MATTER

• Atom The smallest part of an element which
  retains ALL the fundamental properties of the
  element
• Elements - contain only one type of atom
• 1. monatomic elements consist of 1 atom only ex
  Fe, Al, Cu, He
• 2. polyatomic elements consist of several like
  atoms
• bonded together
• Ex H2 O2 Br2 F2 I2 Cl2 P4
  

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III.3 CLASSIFICATION OF MATTER

• A molecule is 2 or more atoms held together
• If a molecule is made up of identical atoms, it
  is called an element.
• If a molecule is made up of different atoms, it
  is called a compound.
• Atoms are held together by electrical forces.

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III.3 CLASSIFICATION OF MATTER

• Difference between an element and a compound?
• First, they are both molecules (2 or more atoms)
• An element is made up of the same type of atoms
• A compound is made up of different types of atoms.

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III.3 CLASSIFICATION OF MATTER

• ION atom or molecule that possesses an
  electrical charge
• Sodium ion (Na )
• Chloride ion (Cl- )
• Nitrate ion or Nitrate ( NO3- )
• A particle general term to describe a small bit
  of matter like atom, molecule, or ion.

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More terms to classify matter

• Pure substance unchanged, uniform properties.
• Ex salt (NaCl) has a density of 2.16 g/mL and
  melts at 801 C and is colourless.
• It is homogenous in composition too!
• Homogenous consisting of only one phase.
• Ex air, water, a piece of iron
• Heterogeneous consisting of more than one phase.
• Ex human beings, pencil, gravel.

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2 types of mixtures

• A mixture a system made up of 2 or more
  substances, and the amounts can be
  different/varied.
• Ex salt dissolved in water.
• If a mixture is heterogeneous, it is called a
  mechanical mixture
• Ex sand, iron filings with sulphur

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Mixture or compound video

• Iron filings and sulphur
• http//www.youtube.com/watch?vcL6I1O1YHH0

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2 types of mixtures

• If a mixture is homogenous, it is called a
  solution.
• gas-in-gas ? our air (hydrogen, oxygen, nitrogen)
  
• gas-in-liquid ? soda, pop cans.
• liquid-in-liquid ? alcohol and water
• THEY LOOK LIKE THERE ARE ONE THING

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Homogeneous solution Heterogeneous solution
Clear solution. Transparent and will not settle Translucent or opaque solution may settle in some cases
Solutes and solvent cannot be separated by filtration or a magnet Can be separated by filtration or a magnet
Salt water, air, alloys Smoke, milk, muddy water

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page 50 Classifying substances scheme
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III.3 CLASSIFICATION OF MATTER

• A solution is a homogeneous mixture of 2 or more
  substances
• A solvent the component in a solution that
  exists in greater amounts.
• A solute the component in a solution that exists
  in lesser amounts

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III.3 CLASSIFICATION OF MATTER
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III.3 CLASSIFICATION OF MATTER

• Aqueous solutions are solutions where the
  solvent is water. The subscript (aq) indicates
  that a compound is in aqueous solution.
• When water exists in solution, we call water
  the solvent EVEN if it exists in LESSER quantity.
  

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• HomeWork for Monday ( for marks )
• QUESTIONS p. 52 33 - 44