Final answer:
A double covalent bond is formed when two atoms share two pairs of electrons, and it is best described as covalent, which involves sharing four electrons in total.
Step-by-step explanation:
The chemical bond formed when two atoms share two pairs of electrons is known as a double covalent bond. It is best described as being strong and involves the sharing of four electrons in total, two from each atom involved. For example, the bond between the two carbon atoms in ethene (C2H4) is a double bond.
A single covalent bond, such as the one found in hydrogen gas (H-H), is formed by the sharing of only one pair of electrons, with each hydrogen atom contributing one electron to the bond formation. In contrast, a double bond involves two shared pairs of electrons, significantly increasing the bond's strength and stability compared to a single bond.