Answer:
Group 18
Step-by-step explanation:
Group 18 comprises of Noble elements (Neon, Krypton, Argon etc). These elements have complete outer shell that is complete octet. According to octet rule, the elements which have less than 8 electrons in their valence shell tend to bond with another element in order to complete their outer shell configuration.
Thus, group 18 elements are least likely to form bonds.