Boron chloride is a covalent compound, meaning it is formed by the sharing of electrons between boron and chlorine atoms. The formula for boron chloride is BCl₃.

Here's how you arrive at that formula:

* Boron (B): Boron is in Group 13 of the periodic table, so it has 3 valence electrons.

* Chlorine (Cl): Chlorine is in Group 17 of the periodic table, so it has 7 valence electrons.

* Sharing Electrons: Boron needs 3 more electrons to complete its octet, while each chlorine atom needs one more electron. To satisfy this, one boron atom shares its three electrons with three chlorine atoms, each forming a single covalent bond.

This results in a molecule with one boron atom and three chlorine atoms, giving the formula BCl₃.