Chapter 5, Problem 110A

Interpretation Introduction

Interpretation:

The new chemical properties of lithium and phosphorus need to be explained, if there are maximum of there electrons in the single orbital.

Concept introduction:

Pauli’s Exclusion Principle states that two electrons cannot have all four quantum numbers same. An orbital can have maximum of two electrons with opposing spins. This means if one spin is assigned as up-spin $\left(+\frac{1}{2}\right)$ then the other spin must be down-spin $\left(-\frac{1}{2}\right)$.

Explanation of Solution

If the Pauli’s Exclusion Principle states that the maximum three electrons, rather than two can occupy a single orbital then in that case, the maximum number of electrons in the s-orbital would be change from two to three which suggests that the total three electrons would make an atom completely stable. According to the new statement of Pauli’s Exclusion Principle, lithium and phosphorus will be noble gases. Lithium will have an electronic configuration of $1s^3$ which is similar to the electronic configuration of the helium that is $1s^2$. The electronic configuration of phosphorus will be $1s^{3}2s^{3}2p^9$ which is equivalent to the electronic configuration of the neon that is $1s^{2}2s^{2}2p^6$. Both atoms lithium and phosphorus would be stable according to the new statement of Pauli’s Exclusion Principle as they have fulfilled orbitals.