Chemical/Physical Properties/Changes

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Properties and Changes in Matter Chapter 20 Glencoe Science

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

Physical Property  How something looks, smells, sounds, or tastes are all examples of physical properties.

Physical Properties  You can detect many physical properties with your senses.

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

Mass

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.

Density  Density measures the amount of mass in a given volume.

 Density = mass/volume  D=m/v

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

Melting Point  The temperature at which a solid changes into a liquid is called its melting point.

Boiling Point  The temperature at which a liquid changes into a gas is called its boiling point.

Magnetism  Magnetism is a physical property.

Chemical Property  A chemical property is a characteristic that cannot be observed without altering the substance.

Chemical Properties  Examples of chemical properties: Flammability, rusting, reacting with substances like acids

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

Changing State  Vaporization is the process by which matter changes from a liquid state to a gas.

Changing State  Condensation is the process where a gas changes into a liquid.

Changing State  Sublimation is the process in which a solid changes directly into a gas.  Ex: dry ice

Changing State  Deposition is the process in which a gas changes into a solid.

Chemical Changes  Chemical changes occur when substances are changed into different substances.

Clues to Chemical Changes  Color change is an example of a chemical change.

Clues to Chemical Changes  Another sign of a chemical change is the release or gain of energy by an object.

Clues to Chemical Changes  The change in odor is a clue to a chemical change.

Signs of Chemical Changes  The production of bubbles is a sign that a chemical change has taken place.

Clues to Chemical Changes  Another clue to a chemical change is the formation of a solid.

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

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

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.

Chemical vs. Physical  Chemical and Physical Changes Game

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