Chapter 8, Problem 98A

Interpretation Introduction

Interpretation:

The reason for doping agent ${\text{AsF}}_{\text{5}}$ to be an exception of the octet rule needs to be explained.

Concept introduction:

According to octet rule, atoms share, lose, or gain electrons to achieve a full set of valence electrons that is eight electrons in outermost shell. Noble gases show stable electron arrangement. This stable arrangement contains complete outer energy level and smaller potential energy compared to other electron arrangement.

Answer to Problem 98A

Doping agent ${\text{AsF}}_{\text{5}}$ is an exception of the octet rule because central atom As shows expanded octet.

Explanation of Solution

The elements of third group do not follow the octet rule because the number of electrons present in the central atom is more than eight. The electron arrangement of this group is referred to as an expanded octet. Arsenic (As) forms five bonds with ten electrons. In ${\text{AsF}}_{\text{5}}$, Arsenic contains electrons more than eight.

Conclusion

An element achieve stable electronic configuration if outermost shell contains eight electrons.