Which one of the following statements about the noble gases is not correct ?

Statement A is incorrect because while most noble gases (Neon, Argon, Krypton, Xenon, and Radon) have a stable octet configuration (eight electrons in their outermost shell), Helium (He) is an exception. Helium has only two electrons in its valence shell, forming a stable duplet configuration ($1s^2$).

• Option B: Noble gases are monoatomic because their valence shells are complete, making them chemically stable enough to exist as single atoms.
• Option C: They are naturally colourless, odourless, and tasteless gases.
• Option D: Although noble gases were once thought to be completely inert, heavier noble gases like Xenon are reactive under specific conditions, forming compounds primarily with highly electronegative elements like Fluorine and Oxygen (e.g., $XeF_2$, $XeO_3$).