This page explains the enhanced function of a wheel rim when combined with a tire for a safe ride. It also discusses combination reactions, where multiple substances unite to form new ones, such as el...This page explains the enhanced function of a wheel rim when combined with a tire for a safe ride. It also discusses combination reactions, where multiple substances unite to form new ones, such as elements reacting with oxygen to create oxides. The text provides examples of balancing equations for these reactions, including potassium oxide formation and the reaction of calcium oxide with water.