Answer:
neon
Step-by-step explanation:
The octet rule states that atoms of elements are stable when they possess 8 electrons on their outermost shell.
Hence, atoms of elements participate in chemical reactions in order to attain this octet structure (eight electrons in the outermost shell).
Neon is a noble gas and already has eight electrons in its outermost shell. Hence, neon is least likely to obey the octet rule.