What is the formula for aluminum oxide (Al2O3)?
The correct answer and explanation is:
The formula for aluminum oxide is Al₂O₃.
This compound is composed of aluminum (Al) and oxygen (O) atoms, and it is commonly found in nature as a mineral called corundum. Aluminum oxide is a simple binary compound, meaning it consists of just two elements: aluminum and oxygen.
Aluminum has a charge of +3 in its ionic form, which is represented as Al³⁺. Oxygen, on the other hand, generally has a charge of -2, represented as O²⁻. To form a neutral compound, the charges of the aluminum ions and oxygen ions must balance out. To achieve this balance, two aluminum ions (with a +3 charge each) combine with three oxide ions (with a -2 charge each). This results in the formula Al₂O₃, where the two aluminum ions provide a total charge of +6, and the three oxide ions provide a total charge of -6, thus balancing the overall charge to zero.
In aluminum oxide, each aluminum ion is surrounded by a coordination of oxygen atoms. The crystal structure of Al₂O₃ is typically hexagonal or trigonal, and it is a key component of many high-strength materials. It also serves as an important part of the production of aluminum metal in the Bayer process, where it is used to extract aluminum from bauxite ore.
Al₂O₃ is also a highly stable compound, resistant to corrosion and high temperatures, making it ideal for use in applications such as ceramics, refractories, and abrasives. Its hardness and high melting point give it significant industrial utility, especially in the creation of materials that need to withstand harsh conditions.