Matter (CHEM111)

Chemistry

The field of study concerned with the characteristics, composition, and transfer of matter.

Matter

Includes all things, both living and non-living; characterized by physical state, properties, and changes.

Physical state

Has three states of matter:solid, liquid, and gas.

Solid

Characterized by a definite shape and a definite volume.

Liquid

Characterized by an indefinite shape and a definite volume.

Gas

Characterized by an indefinite shape and volume.

Property

Distinguishing characteristic of a substance used in its identification and description; includes physical and chemical properties.

Physical property

Characteristics that can be observed without changing the basic identity of the substance (e.g., color, odor, melting/boiling point).

Chemical property

Describes how a substance undergoes or resists change to form a new substance.

Physical changes

Changes in physical appearance without altering chemical composition.

Chemical changes

Changes in chemical composition that convert material into one or more new substances.

Pure substance

A single kind of matter that cannot be separated into other kinds by physical means (e.g., pure water).

Mixture

Physical combination of two or more pure substances, each retaining its own chemical identity; components can be separated using physical means.

Heterogeneous mixture

A mixture containing visibly different phases, each with different properties.

Homogeneous mixture

A mixture with only one visible distinct phase, having uniform properties throughout (e.g., sugar water).

Element

A pure substance that cannot be broken down into simpler substances by chemical means (e.g., gold, hydrogen).

Compound

A pure substance that can be broken down into two or more simpler substances by chemical means (e.g., water).

Physical combination

Produces a mixture without binding.

Chemical combination

Produces a compound with binding between entities.

Chemical symbol

One or two-letter designation for an element derived from its name.

Atom

The smallest particle of an element that retains the properties of that element.

Molecule

A group of two or more atoms that functions as a unit due to tight binding.

Diatomic molecule

A molecule containing two atoms.

Triatomic molecule

A molecule containing three atoms.

Homoatomic molecule

A molecule with all atoms of the same kind (e.g., H2, O2).

Heteratomic molecule

A molecule with two or more kinds of atoms (e.g., H2O).

Compounds

Molecules made of atoms from different elements.

Chemical formula

Notation made up of chemical symbols and numerical subscripts indicating the number of atoms of each element in a compound.