Chemistry: Physical and Chemical Changes

Physical Property

Characteristic, can be determined without altering or changing substances

Chemical Property

The ability of a substance to form new substances

Physical Change

Any change in a property that does not result in a change in the identity of a substance

Chemical Change

Any change in a substance that results in the change in the identity of a substance, that results in different characteristic properties of the substance

Indications of Chemical Change

Color Change, Evolution of heat and light/ or change, Production of gas, Formation if a precipitate (clump)

Pure Substance

Matter with a definite, fixed composition, they can be either elements or compounds

Elements

Contains only one kind of atom. Cannot be broken down into simpler substances

Compounds

Substances that contain two or more kinds of atoms that are chemically combined. Can be broken down chemically into elements

Mixture

A material containing two or more pure substances that are not chemically combined. Variable composition. Can be separated into pure substances by various means. It is either: heterogeneous or homogeneous

Homogeneous

Is uniform in appearance, same properties throughout, is also called a solution

Heterogeneous

Matter having two or more distinct phases, Different properties in different parts of the mixture

Solutions

Solvent (part one)- does the dissolving

Solute (part two)- gets dissolved

Water solutions are aqueous (aq) and solid solutions are called alloys