* It is made up of two or more different elements. Borax is composed of boron (B), oxygen (O), sodium (Na), and hydrogen (H).
* The elements are chemically combined in a fixed ratio. The chemical formula for borax is Na₂B₄O₇·10H₂O, which indicates a specific ratio of each element.
* It has properties distinct from the individual elements. Borax is a white, crystalline powder that dissolves in water, whereas boron is a hard, black solid, oxygen is a colorless gas, sodium is a soft, silvery metal, and hydrogen is a colorless, odorless gas.
Therefore, due to its composition of different elements in a fixed ratio and its unique properties, borax is classified as a compound.
