Matter: Properties and Changes

1
Matter Properties and Changes

• How can we classify Matter?

2
Matter

• Is anything that has mass and takes up space
• Is the measure of the amount of matter in an
  object
• All material or stuff around us is matter

3
Properties of Matter

• The characteristics that are used to identify
  matter and distinguish them from one another are
  called properties. These properties are grouped
  into two broad categories physical properties
  and chemical properties.

4
Physical Properties

• Physical properties of matter are usually those
  that can be observed with the senses.
• It identifies the substance without causing a
  change in the composition of the substance.

5
Substance

• Matter that has uniform and unchanging
  composition
• Ex H20 is a pure substance and no matter where
  it is found it will have the same composition as
  any other sample of water

6
Intensive Property

• Property that remains the same no matter how much
  of a substance you have.
• Ex Density, MP, BP

7
Extensive Property

• Property that is dependent on the amount of
  substance present.
• Ex mass, length, volume

8
Some Examples of Physical Properties

• physical state (solid, liquid or gas at certain
  temperatures and pressures)
• color, odor, size, shape, volume,
• melting point or boiling point
• hardness (or softness)
• solubility - the ability of substance to dissolve
• density mass/volume
• ductility the ability to be drawn into a thin
  wire
• malleability - the ability to be hammered into a
  thin sheet
• conductivity can conduct heat and/or
  electricity
• flexible, brittle, volatile, lustrous (shine)

9
Examples of Physical Properties

• Sulfur is yellow brittle.

Metals are malleable. What does that mean? Look
at your notes from the last slide.
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Chemical Properties

• Chemical properties of matter are those that
  relate to
• how the substance changes in composition
• how it interacts with other substances.
• Basically, the ability or inability of a
  substance to combine with or change into other
  substances
• There really isn't a set of chemical properties
  in the same way there is, more or less, a set of
  physical properties. That's because the chemical
  properties are tied to the change.

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Some Examples of Chemical Properties

• Flammability
• Iron reacts with oxygen to form rust
• Glucose, mixed with yeast, ferments to make
  alcohol and carbon dioxide
• Combustibility
• Copper forms copper carbonate (Patina) when in
  contact with moist air
• Inability of gold to combine with other
  substances

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Practice Problems Label - Physical or Chemical
Property

1. Silver tarnishes when it comes into contact with
   hydrogen sulfide in the air.
2. A sheet of copper can be pounded into a bowl
3. Barium melted at 725oC
4. Helium does not react with any other element

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Practice Problems

• 5. A bar of lead is more easily bent than is a
  bar of aluminum of the same size
• 6. Potassium metal is kept submerged in oil to
  prevent contact with oxygen or water
• 7. Diamond dust can be used to cut or grind most
  other materials
• 8. Rocks containing carbonates can be identified
  because they fizz when hydrochloric acid is
  applied

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Answers to Practice Problems

1. Chemical
2. Physical
3. Physical
4. Chemical
5. Physical
6. Chemical
7. Physical
8. Chemical

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Matter can also be classified as

• A Physical change
• or
• A Chemical change

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Physical Changes

• Physical changes are those changes that do not
  result in the production of a new substance or do
  not alter the composition of the matter.
•  
• If you melt a block of ice, you still have H2O at
  the end of the change. 
• If you break a bottle, you still have glass. 
• Painting a piece of wood will not make it stop
  being wood. 

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Examples of Physical Changes

• Some common examples of physical
• changes are
• Changes of state melting, freezing, condensing,
  boiling
• Breaking
• Crushing
• Cutting
• Bending

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Chemical Changes

• Chemical changes, or chemical reactions, are
  changes that result in the production of new
  substances.
•  
• When you burn a log in a fireplace, you are
  carrying out a chemical reaction that releases
  carbon. 
• When you light your Bunsen burner in lab, you are
  carrying out a chemical reaction that produces
  water and carbon dioxide. 

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Chemical Changes

• Also known as a chemical reaction
• In a chemical reaction the starting substances
  are known as the reactants and the substances
  formed are called the products.
• 2H2 O2 ? 2H2O
• (Reactants) (Product)
• A chemical reaction shows the relationship
  between the reactants and products

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Examples of Chemical Changes

• Common examples of chemical
• changes that you may be familiar
• with are
• digestion
• respiration
• photosynthesis
• burning
• decomposition 

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Practice Problems Label - Physical or Chemical
Change

1. Moisture in the air forms beads of water on a
   cold window pane
2. An electrical current changes water into hydrogen
   and oxygen
3. Yeast cells in bread dough make carbon dioxide
   and ethanol from sugar
4. Olive oil, vinegar, salt and pepper are shaken
   together to make salad dressing
5. Molten bronze is poured into a mold and
   solidifies to form a figurine
6. A reactant decomposes to form two products

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Answers to Practice Problems

1. Physical
2. Chemical
3. Chemical
4. Physical
5. Physical
6. Chemical

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The End