Use the terms in the boxes to fill in the blanks in the following paragraphs.

Atoms, Balanced, Chemical Reaction, Coefficients, Correct, Element, Equation, Formula, Mass, Mg, Numbers, Products, Reactants, Substance, Two, Yields

A ___________________________ is a well defined example of a chemical change. A chemical ___________________________ can be used to show the changes that occur in a chemical reaction. In a chemical reaction, the substance on the left side of the arrow are the starting substance. These substances are called ___________________________. The substances on the right side of the arrow are the substances that result from the reaction. These substances are called ___________________________. The arrow is read as either produces or ___________________________. According to the law of conservation of ___________________________, atoms are neither lost nor gained during a chemical reaction. This law is illustrated when a chemical equation is ___________________. When this is done, there will be the same number of ___________________________ of each kind on both sides of the equation. In a chemical equation, the numbers that are placed in front of the symbols and the formulas are called ___________________________. They are necessary to keep the ___________________________ of atoms in balance. There are several rules for balancing an equation. First, write the correct _________________________ for each reactant and product. Next, choose the coefficients that make the number of atoms of each ___________________________ on each side of the equation equal. The correctly written formula should not be changed. If you change the formula of a substance, the equation is no longer ________________________. Changing a formula will indicate a ___________________________ different than the one intended. To balance the equation Mg + O2 à MgO, first choose coefficients to make the number of atoms of each element on each side of the equation equal. You would need to place a coefficient of ____________________