Final answer:
Neon, Argon, Krypton, and Xenon are classified as noble gases (Group 18), known for their low reactivity due to their filled valence electron shells, although the first compounds containing noble gases were synthesized in 1962. Option A is correct.
Step-by-step explanation:
Neon, Argon, Krypton, and Xenon are part of a group known as noble gases. The elements in group 18 of the periodic table, including helium and radon, are referred to as noble gases due to their extremely low reactivity resulting from their filled valence electron shells.
Noble gases are monatomic and were once thought to be completely nonreactive, earning the term "inert gases." However, in 1962, compounds containing noble gases were synthesized for the first time by Dr. Neil Bartlett, disproving the assumption of their complete inertness.
These gases have various applications due to their relative lack of chemical reactivity. Argon is frequently used in an inert atmosphere for welding and in light bulbs, while the red light of neon is iconic in neon signs. Despite their low natural abundance, noble gases play essential roles in various industries.