The chemical composition of an aluminum coil is primarily aluminum (Al), which is a lightweight, malleable, and ductile metal. It is usually represented by its elemental symbol 'Al' and has an atomic number of 13. Aluminum is often alloyed with other elements to improve its strength and performance. Common alloying elements include copper (Cu), magnesium (Mg), manganese (Mn), silicon (Si), and zinc (Zn). These elements are added in varying percentages depending on the specific properties required for the aluminum coil's application. The purity of aluminum in a coil can range from 99.00% to 99.7%, with the remainder being trace amounts of other elements.