Here's why:

* Electronegativity: Chlorine (Cl) and Oxygen (O) are both nonmetals and have relatively high electronegativity values. The difference in electronegativity between them is not large enough to form an ionic bond.

* Bonding: The atoms in Cl₂O share electrons to form covalent bonds. The central oxygen atom forms a double bond with one chlorine atom and a single bond with the other chlorine atom.

Therefore, Cl₂O is a covalent compound due to the sharing of electrons between its constituent atoms.