Properties and Changes in Matter

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Properties and Changes in Matter

• Chapter 20
• Glencoe Science

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Physical Property

• A characteristic that you can observe without
  changing or trying to change the composition of
  the substance.

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Physical Property

• How something looks, smells, sounds, or tastes
  are all examples of physical properties.

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Physical Properties

• You can detect many physical properties with your
  senses.

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Mass

• Mass is a measurement of how much matter an
  object contains.

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Weight

• Weight is a measurement of force.
• Weight depends on the mass of the object and on
  gravity.
• No matter where you are in the universe your mass
  never changes, but your weight can.

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Density

• Density measures the amount of mass in a given
  volume.
• Density mass/volume
• Dm/v

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Solubility

• Solubility is the ability of one substance to
  dissolve into another substance.

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Melting Point

• The temperature at which a solid changes into a
  liquid is called its melting point.

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Boiling Point

• The temperature at which a liquid changes into a
  gas is called its boiling point.

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Magnetism

• Magnetism is a physical property.

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Chemical Property

• A chemical property is a characteristic that
  cannot be observed without altering the substance.

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Chemical Properties

• Examples of chemical properties
• Flammability, rusting, reacting with substances
  like acids

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Physical Changes

• A physical change is one in which the form or
  appearance of matter changes, but not its
  composition.

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Changing State

• Vaporization is the process by which matter
  changes from a liquid state to a gas.

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Changing State

• Condensation is the process where a gas changes
  into a liquid.

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Changing State

• Sublimation is the process in which a solid
  changes directly into a gas.
• Ex dry ice

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Changing State

• Deposition is the process in which a gas changes
  into a solid.

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Chemical Changes

• Chemical changes occur when substances are
  changed into different substances.

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Clues to Chemical Changes

• Color change is an example of a chemical change.

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Clues to Chemical Changes

• Another sign of a chemical change is the release
  or gain of energy by an object.

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Clues to Chemical Changes

• The change in odor is a clue to a chemical change.

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Signs of Chemical Changes

• The production of bubbles is a sign that a
  chemical change has taken place.

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Clues to Chemical Changes

• Another clue to a chemical change is the
  formation of a solid.

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Chemical Changes

• The substances produced during a chemical change
  cannot be changed back into the original
  substances by physical means.

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Chemical vs. Physical

• During a physical change the composition of the
  substance does not change, but during a chemical
  change the composition of the substance does
  change.

Chemical change
Physical change
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Conservation of Mass

• Law of conservation of mass states that mass is
  neither created nor destroyed. As a result the
  mass of the substances before a physical or
  chemical change is equal to the mass of the
  substances present after the change.

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Chemical vs. Physical

• Chemical and Physical Changes Game