Chem Notes Properties

Physical properties

Can be observed without changing the substance's identity.

Chemical properties

Can only be observed by changing the substance's chemical identity.

Density

A physical property that describes the mass per unit volume of a substance.

Boiling point

The temperature at which a substance transitions from a liquid to a gas; a physical property.

Melting point

The temperature at which a substance transitions from a solid to a liquid; a physical property.

Solubility

A physical property that indicates how well a substance dissolves in a solvent.

Flammability

A chemical property that indicates how easily a substance can ignite and burn.

Reactivity

A chemical property that describes how a substance interacts with other substances, such as water or acid.

Toxicity

A chemical property that indicates how harmful a substance can be to living organisms.

Intensive properties

Do not depend on the amount of matter present.

Extensive properties

Change depending on the amount of matter present.

Temperature

An intensive property that measures the average kinetic energy of particles in a substance.

Color

An intensive property that describes the visual characteristic of a substance.

Mass

An extensive property that measures the amount of matter in a substance.

Volume

An extensive property that describes the space occupied by a substance.

Length

An extensive property that measures one dimension of a substance.

Solids

State of matter with a definite shape and a definite volume.

Liquid particles

Are close together but can slide past each other, allowing liquids to take the shape of their container.

Gases

State of matter that has an indefinite shape and an indefinite volume.

Physical changes

Alter the form of a substance but not its chemical identity.

Chemical changes

Create entirely new substances with new chemical properties.

Phase changes

Always physical changes, including melting, boiling, and freezing.

Dissolving sugar

A physical change that occurs when sugar mixes with water.

Burning wood

A chemical change that produces ash, smoke, and gases.

Rusting iron

A chemical change that occurs when iron reacts with oxygen and moisture.

Color changes

Often indicate a chemical change in a substance.

Gas bubble formation

A common indicator of a chemical change.

Precipitate formation

Indicates a chemical change when a solid forms from two liquids.

Temperature changes

Without outside heating, can indicate a chemical change.