When two chlorine atoms combine with each other, they form a covalent bond.

Here's why:

* Chlorine's Electron Configuration: Each chlorine atom has 7 electrons in its outermost shell (valence shell). It needs one more electron to achieve a stable octet configuration.

* Sharing Electrons: To achieve stability, two chlorine atoms share their single valence electrons. This sharing forms a single covalent bond.

* Diatomic Molecule: The result is a diatomic molecule, Cl₂, where each chlorine atom is now surrounded by eight electrons (two from its own atom and six from the shared bond).