* Electronegativity: Boron has an electronegativity of 2.04, and iodine has an electronegativity of 2.66. The difference in electronegativity between them is 0.62, which is not large enough to form an ionic bond.

* Bonding Type: Covalent bonds form when atoms share electrons to achieve a stable electron configuration. The electronegativity difference between boron and iodine indicates a sharing of electrons, leading to a covalent bond.

Therefore, the compound formed between boron and iodine is covalent.