Chemical Reactions and Equations

Chemical Bond

An interaction that holds two atoms together

Chemical Reaction

A process where one or more substances change to make one or more new substances

Precipitate

Solid substance formed in a solution

Chemical Properties

Characteristic properties that can be used to identify a pure substance; substance is changed during observation. Example: reactivity

Physical Properties

Characteristic property that can be used to identify a pure substance; substance is NOT changed chemically during observation. Example: state of matter

Chemical Formula

Shorthand way to write a compound's name using chemical symbols and subscripts; shows how many and what kind of elements

Chemical Symbol

One or two letter abbreviation for an element

Subscript

Number to the lower right of a chemical symbol; indicates how many atoms of that element are in the compound

Chemical Equation

Use of chemical symbols and formulas to indicate a chemical reaction

Reactants

Starting materials in a chemical reaction

Products

Ending materials in a chemical reaction

Coefficient

Number in front of a chemical formula indicating how many of that atom or molecule are needed in an equation

Law of Conservation of Mass

The mass of the reactants is equal to the mass of the products

synthesis reaction

a reaction in which two or more substances combine to form a new compound

decomposition reaction

a reaction in which a single compound breaks down to form two or more simpler substances

Single Displacement/Replacement reaction

one element replaces a similar element in a compound

Double Displacement/Replacement reaction

a chemical reaction where two compounds react to form two or more new compounds by switching ionic partners (positive & negative ions switch)

combustion reaction

a chemical reaction that occurs when a substance reacts with oxygen, releasing energy in the form of heat and light