Non polar covalent bond. The Cl's electronegativity is the same since it's the same atom. Therefore, they will be nonpolar
Using a calculator:
(2.568 x 5.8)/4.186 = 3.5581460…
= 3.56 (3sf)
You didn’t specify the correct number of significant figures needed.
A lone oxygen atom has 6 electrons in its outer shell which is not very stable, whereas as full octet (8 outer shell electrons) is stable. In order to achieve this two oxygen atoms will share 4 electrons, each contributing 2 electrons. Since these electrons exist within the orbitals of both atoms, to oxygen atoms essentially achieve a full octet.
Br2 is the correct answer