Chemical change – the formation of a new substance with different properties; cannot be undone by physical means

Chemical formula – a representation of a compound in which the elements are represented by their symbols and subscripts represent the number of atoms of each element

Chemical reaction – a change caused by the interaction of two or more substances resulting in the formation of new substances

Chemical symbol – representation of the name of an element; written as a capital letter or a capital letter followed by a lowercase letter(s)

Compound – a pure substance made by chemically combining two or more elements; represented by a chemical formula

Element – a pure substance that cannot be broken down chemically into simpler substances

Physical change – change which alters the physical properties of a substance without changing its identity

Precipitate – the solid that is formed as a result of a precipitation reaction

Pure substance – a substance that is not mixed with any other substance

Subscript – the number written to the right and slightly below an element in a chemical formula; represents the number of atoms of an element present in a chemical formula