What is a chemical change?

A chemical change is when something is changed to form a new substance different from the old substances. Chemical changes often forms tarnish, changes color, releases gas, forms a precipitate, or releases energy.

Compounds

A compound is a mix of two or more elements to form a new substance. It is a chemical change.

All compounds have chemical names and formulas.

A chemical name is the name of which substances combine to form the compound. The chemical name for rust(iron and oxygen) is iron oxide.

A chemical formula is the symbol of the elements and the number of molecules per element that make a compound. The chemical formula for rust is Fe2O3.

How chemical changes are used.

Photosynthesis and respiration are two chemical changes used by plants and animals. A space shuttle uses the energy given off by chemical changes to escape earth’s atmosphere. Chemical changes are used in many ways.