Properties of Substances & Separation Techniques

Physical properties

Characteristics of a substance that can be observed or measured without changing the substance's composition.

Pure substance

A material that is composed of only one type of particle.

Intensive property

A property that does not depend on the amount of the material.

Extensive property

A property that depends on the amount of the material.

Mixture

A physical blend of two or more substances.

Homogeneous mixture

A mixture that is uniform in composition.

Heterogeneous mixture

A mixture that is not uniform in composition.

Distillation

A process that separates substances based on differences in their boiling points.

Filtration

A technique that separates solids from liquids in a heterogeneous mixture.

Elements

Substances that cannot be broken down into simpler substances by chemical means.

Compounds

Substances composed of two or more elements chemically combined in fixed proportions.

Chemical properties

Properties that describe the ability of a substance to undergo chemical reactions and change into new substances.

Chemical changes

Changes that result in the formation of new substances with different properties.

Physical changes

Changes that alter the form of a substance without changing its chemical identity.

Percent error

A measure of how inaccurate a measurement is, calculated as the difference between the experimental and accepted values divided by the accepted value, multiplied by 100%.

Dimensional analysis

A method of converting units by using conversion factors that relate different units to each other.

Significant figures

Digits in a measurement that are known with certainty plus one uncertain digit.