Chemical/Physical Properties/Changes


Properties and Changes in


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.



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 measures the amount of mass in a given volume.

Density = mass/volume



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 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


Color change is an example of a chemical change.

Clues to Chemical


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

Clues to Chemical


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

Signs of Chemical


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

Clues to Chemical


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