Answer:
Covalent bond.
Step-by-step explanation:
From the question given above, we can see that each chlorine atom donate 1 electron to form bond thereby attaining a stable octet configuration. This simply indicates covalent bond.
Covalent bond is a type of bond in which there is a sharing of electron(s) between the atoms involved in the bond.
In the diagram given above, each chlorine atoms has 7 electrons in their outmost shell and requires 1 electron to complete their octet configuration. Hence the two chlorine atom will share one electron each in order to attain a stable octet configuration.