Texas A&M University (TAMU) CHEM107 General Chemistry for Engineering Students Exam 2 Practice

The significance of a complete octet in noble gases primarily lies in its role in promoting stability and low reactivity. Noble gases, such as helium, neon, argon, krypton, xenon, and radon, have electron configurations that fill their outermost electron shell, achieving a total of eight valence electrons (with the exception of helium, which has a complete shell with just two electrons). This filled outer shell configuration translates into a highly stable electron arrangement.

Because noble gases have achieved this electrically neutral and stable state, they do not readily form bonds with other elements, which is indicative of low reactivity. The tendency of atoms to achieve a complete octet is rooted in the octet rule, which states that atoms are most stable when they have eight electrons in their valence shell. Therefore, noble gases exemplify this stability by remaining inert and unreactive in typical conditions, as they do not need to gain, lose, or share electrons to achieve a more stable configuration.

This characteristic of noble gases is fundamental for understanding the behavior of not only noble gases themselves but also of other elements that seek to emulate their stability through bonding and electron exchange.