The original substances in a chemical reaction are called reactants. The products are the new substances produced by the chemical change. Bubbles in soda appear during a(n) decomposition reaction. An example of a(n) synthesis reaction is the rusting of steel wool. During a replacement reaction, one element replaces another in a(n) compound. Elements’ chemical properties can be predicted from their periodic table positions. Elements in the first column react immediately on contact with water. Elements in the last column, called the noble gases, rarely form compounds with other elements. Metals in the middle column are more stable than sodium. For this reason, these elements are used to produce coins.