The Nature and Separation of Matter

What is chemistry?

The science of the composition, structure, properties and reactions of matter.

How is matter defined?

Anything that occupies space and has mass.

What are the two broad classifications of matter?

Pure substances and mixtures.

What is a pure substance?

A homogeneous material made up of only one kind of matter with a definite, fixed composition.

What is an element?

A pure substance that cannot be decomposed or transformed into other elements by chemical means.

What are compounds?

Substances of two or more elements that are chemically combined in definite proportions.

How are acidic substances defined?

A substance that gives H+ in a solution, turns blue litmus paper red, and has a sour taste.

What is a base?

A substance that gives OH- in a solution, turns red litmus paper blue, and has a bitter taste.

What is a mixture?

A combination of two or more elements and/or compounds that retain their chemical identities.

What is a homogeneous mixture?

A mixture where components are evenly distributed and cannot be distinguished from one another.

What are the four states of matter?

Solid, Liquid, Gas, and Plasma.

What do solids have regarding particle arrangement?

Particles are tightly packed, vibrating about a fixed position.

What defines a physical property?

Inherent characteristics of a substance that can be determined without altering its composition.

What is a physical change?

A change in physical properties or changes in state without a change in composition.

What is filtration?

A method that separates a solid from a fluid by passing the mixture through a porous material.

What is chromatography used for?

To separate dissolved substances in a solution based on differential movement through a stationary and mobile phase.

What is distillation?

A method used to separate homogeneous mixtures based on differences in boiling points of substances involved.

What is crystallization?

A separation technique that results in the formation of pure solid particles from a solution.

What is meant by an electrolyte?

A compound whose aqueous solution or molten state conducts electricity.

What is an intensive property?

A property that depends on the kind of material, such as melting point, boiling point, or density.