B₂Si is a covalent compound consisting of two boron atoms and one silicon atom bonded together by sharing electrons. This compound is known as boron silicide or diborane silicide and is commonly used in the production of semiconductors, ceramics and other high-temperature materials.

Covalent compounds are compounds formed by the sharing of electron pairs between two atoms. Covalent compounds have covalent bonds between atoms. They do this to gain stability, and the number of covalent bonds formed depends on the electrons present in the outermost layer or their valence.