JAMB Chemistry 2015 Paper

Concept:The stability of rare gases is best explained by their electronic configuration rather than their physical properties.Explanation:Rare gases are stable because their outermost shells are completely filled with electrons.Helium follows the duplet rule, having the configuration $1s^2$.Other rare gases, such as neon and argon, follow the octet rule, having the configuration $ns^2np^6$.A completely filled outermost shell makes the atoms chemically inert and highly stable.These gases do not lose, gain, or share electrons easily, so they rarely form ions.Rare gases exist as monoatomic gases, but this is a result of their stability rather than the cause of it.Similarly, being volatile does not explain their lack of chemical reactivity.Answer:C. have duplet or octet electronic configuration in the outermost shells in their atoms