Which among the following is the correct composition of Borax ?

Borax, also known as sodium tetraborate or sodium borate, is a naturally occurring mineral and a salt of boric acid. Its chemical composition consists of the elements Sodium (Na), Boron (B), Oxygen (O), and Hydrogen (H).

The common chemical formula for Borax is Na2B4O7·10H2O (Sodium tetraborate decahydrate). In its structural form, it is represented as Na2[B4O5(OH)4]·8H2O. Based on these formulas, the constituent elements are clearly identified as follows:

• Sodium: Present as the cation.
• Boron and Oxygen: Form the tetraborate cluster.
• Hydrogen and Oxygen: Present in the form of hydroxyl groups and water of crystallization.

Borax is widely used in various industrial and household applications, including as a cleaning agent, a pH buffer, and in the manufacturing of heat-resistant glass (borosilicate glass).