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Physical and Chemical Properties and Changes


Physical and Chemical Properties and Changes Page 18 and 19 Page 28 30 Page 34 35 Page 38 - 39 Page 18 - 19 Chemical Properties of Matter When one substance ... – PowerPoint PPT presentation

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Title: Physical and Chemical Properties and Changes

Physical and Chemical Properties and Changes
  • Page 18 and 19
  • Page 28 30
  • Page 34 35
  • Page 38 - 39

Page 18 - 19
  • Chemical Properties of MatterWhen one substance
    can interact with another, the characteristic
    behaviour is called a chemical property. Ie.
    Dynamite explodes when exposed to a flame and
    mixes with oxygen in the air.

  • Chemical PropertyA chemical property describes
    the behaviour of a substance as it becomes a new
  • Combustibility
  • Combustibility is a property that describes the
    ability of a substance to react with oxygen to
    produce carbon dioxide, water and energy.
    Combustible is flammable non-combustible is

  • Reaction with acid
  • Another chemical property of matter is reaction
    with acid. For example, when magnesium metal is
    added to acid, it produces bubbles of gas and the
    metal disappears. Limestone is identified by
    its reaction to acid bubbles of gas are
    produced when they come in contact.
  • Metals and Nonmetals
  • Matter can be grouped as metals and nonmetals.
    Mixtures of metals are alloys. Examples are
    braces, cooking pots and airplanes.

Physical and Chemical Changes
  • ARE NOT THE SAMEasPhysical and Chemical
  • we have studied so far.

A burning candle what happens?
  • As the candle burns, the wax melts (a solid
    becomes a liquid), and then it hardens (a liquid
    becomes a solid). These are physical changes.
  • The wax also combusts producing heat and light.
    This chemical change involves the wax becoming
    carbon dioxide, water and energy.

Physical and Chemical Changes(Not the same as
Phys. and Chem. Properties)
  • Physical Change The substance involved remains
    the same, even though it may change state or
  • Ex. Pour melted chocolate on ice cream.
  • It still tastes the same because the particles
    have not changed, it just hardened (changed
    state) because the ice cream was cool.
  • Most physical changes are easy to reverse.

  • Chemical Changes The original substance is
    changed into one or more different substances
    that have different properties.
  • Examples
  • Burning, Cooking, Rusting
  • The formation of water from hydrogen and oxygen.
  • The formation of rust from iron and oxygen.
  • Chemical changes are difficult to reverse.

  • There are usually clues that a chemical change
    has happened
  • A new colour appears.
  • Heat or light is given off.
  • Bubbles of gas are given off.
  • A solid material (called a precipitate) forms in
    a liquid.
  • The change is difficult to reverse.

  • 1. Copy Table 2, page 30 in your notebook.
  • 2. Read pages 28-30 and on page 30 answer
    questions 1-4. Copy the questions and the
    answers into your notebook.

Page 30 questions 1-4
  • 1. Explain how a physical change differs from a
    chemical change.
  • Chemical changes involve production of a new
    substance with new properties. No new substances
    are produced in physical changes.

  • 2. a) Garbage rotting
  • chemical
  • b) Cutting up carrots
  • physical
  • c) A silver spoon turning black
  • chemical
  • d) Making tea from tea leaves
  • physical
  • e) Bleaching a stain
  • chemical
  • f) Boiling an egg
  • chemical

Question 3
  • Changes occur more quickly at high temperatures.
    Putting candles together tends to concentrate
    heat more and the candles will be at a higher
  • For emergencies, non-dripping and non-smoking
    candles should be kept on hand.
  • (or battery operated)

Question 4
  • Evaporation, mixing, and condensation are
    physical changes.
  • Combustion, catalytic conversion and rusting are
    chemical changes.


Sample Chemical Changes (Always involve the
production of a new substance.)
  • Ex. 1 H O ? H2O (water)
  • gas gas liquid
  • Reactants Left side Products Right
  • Ex. 2
  • C 2O ? CO2 (carbon dioxide)
  • Ex. 3
  • 6C 12H 6O ? C6H12O6 (sugar)
  • Ex. 4
  • 3C 8H ? C3H8 (Propane)
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