1.2 Macroscopic and Particulate Views of Matter

Vocabulary flashcards covering key concepts from 1.2 Macroscopic and Particulate Views of Matter.

Element

A pure substance that cannot be broken down into simpler substances.

Compound

A substance composed of two or more elements in fixed proportions; can be separated into elements only by a chemical reaction.

Pure substance

Matter with a constant composition that does not vary from one sample to another; cannot be separated into simpler substances by physical processes.

Mixture

A form of matter composed of two or more substances that retain their own identities and are not present in fixed proportions; can be separated by physical methods.

Homogeneous mixture

A mixture in which the substances are uniformly distributed, with the same composition throughout.

Heterogeneous mixture

A mixture in which the components are not distributed uniformly and can have distinct phases.

Physical process

A transformation that does not alter the chemical identities of the substances (e.g., a change of state from solid to liquid).

Chemical reaction

The transformation of one or more substances into one or more different substances.

Atom

The basic unit of an element; the smallest unit of an element.

Molecule

The smallest unit of a compound formed by chemical bonds between two or more atoms.

Water (H2O)

A pure substance and a compound composed of two hydrogen atoms and one oxygen atom.

Sodium chloride (NaCl)

Common table salt; a compound with properties distinct from its elements.

Vinegar

A homogeneous mixture of acetic acid and water.

Salad dressing

A heterogeneous mixture where solids may be suspended in a liquid and may settle.

Periodic table

A tabular arrangement of all known elements.