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