Properties and Changes in Matter

Chapter 20 Glencoe Science

Physical PropertyPhysical Property

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

Physical PropertyPhysical Property

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

Physical PropertiesPhysical Properties

You can detect many physical properties with your senses.

Mass Mass

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

WeightWeightWeight 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.

DensityDensity

Density measures the amount of mass in a given volume.

Density = mass/volume

D=m/v

SolubilitySolubility

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

Melting PointMelting Point

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

Boiling PointBoiling Point

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

MagnetismMagnetism

Magnetism is a physical property.

Chemical PropertyChemical Property

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

Chemical PropertiesChemical Properties

Examples of chemical properties:

Flammability, rusting, reacting with substances like acids

Physical ChangesPhysical Changes

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

Changing StateChanging State

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

Changing StateChanging State

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

Changing StateChanging State

Sublimation is the process in which a solid changes directly into a gas.

Ex: dry ice

Changing StateChanging State

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

Chemical ChangesChemical Changes

Chemical changes occur when substances are changed into different substances.

Clues to Chemical Clues to Chemical ChangesChanges

Color change is an example of a chemical change.

Clues to Chemical Clues to Chemical ChangesChanges

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

Clues to Chemical Clues to Chemical ChangesChanges

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

Signs of Chemical Signs of Chemical ChangesChanges

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

Clues to Chemical Clues to Chemical ChangesChanges

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

Chemical ChangesChemical Changes

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

Chemical vs. PhysicalChemical 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 MassConservation 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. PhysicalChemical vs. Physical Chemical and Physical Changes Game