States of Matter & Pure Substances and Mixture

Chemistry

is the study of matter—its composition,

properties, and transformations.

Matter

is anything that has mass and takes up volume

Solid

has a definite volume

maintains its shape regardless of its container

has particles that lie close together in a regular three-dimensional array

Liquid

has definite volume

takes the shape of its container

has particles that are close together but can move past one another

Gas

has no definite shape or volume

expands to fill the volume and assumes the shape of whatever container it is put in

has particles that are very far apart and move around randomly

Physical properties

can be observed or measured without changing the composition of the material

Physical change

alters the material without changing its composition.

Chemical properties

determine how a substance can be converted into another substance.

Chemical change

is the chemical reaction that converts one substance into another.

pure substance

is composed of a single component

has a constant composition, regardless of sample size and origin of sample

cannot be broken down to other pure substances by a physical change

mixture

is composed of more than one component

can have varying composition (any combination of solid, liquid, and gas), depending on the sample

can be separated into its components by a physical change

element

is a pure substance that cannot be broken down by a chemical change.

compound

is a pure substance formed by chemically joining two or more elements.