Matter

Accuracy

How close a measurement is to the accepted value

Precision

How close repeated measurements are to each other

Analog Device

Record all certain digits plus one estimated digit

Digital Device

Record every digit shown

Pure Substance

Matter made of only one substance

Mixture

Two or more substances physically combined

Homogenous Mixture

Mixture that is uniform throughout

Heterogenous Mixture

Mixture that is not uniform throughout

Element

Substance made of only one type of atom

Compound

Two or more different elements chemically bonded

Physical Property

Property that can be observed without changing the substance

Chemical Property

Property describing how a substance can form new substances

Physical Change

Change that does not form a new substance

Chemical Change

Change that forms one or more new substances

Phase Change

Change in state where the substance remains chemically the same

Melting

Solid to liquid

Freezing

Liquid to solid

Evaporation/Vaporization

Liquid to gas

Condensation

Gas to liquid

Sublimation

Solid to gas

Deposition

Gas to solid

Reactants

Substances present before a chemical reaction

Products

Substances formed by a chemical reaction

Law of Conservation of Mass

Mass cannot be created or destroyed in a chemical reaction

Conservation of Mass Equation

Mass of Reactants = Mass of Products

Significant Figures

Digits that show the precision of a measurement