Chapter 8, Problem 8.25QE

(a)

Interpretation Introduction

Interpretation:

The electronic configuration of $\text{P}$ from its location in the periodic table has to be determined.

Concept Introduction:

The electronic configuration is defined as the distribution of electrons in various atomic orbitals of the atom. The electrons that are present in outermost orbital are known as valence electrons whereas those present in the orbitals with lower quantum numbers are called core electrons. The general outer electronic configuration of $s\text{block}$ elements is $n{s}^{1-2}$, that of $p\text{block}$ elements is $n{s}^{2}n{p}^{1-6}$, that of $d-\text{block}$ elements is $\left(n-1\right)d^{1-10}n{s}^{0-2}$ and that of $f\text{block}$ elements is $\left(n-2\right)f^{1-14}\left(n-1\right)d^{0-10}n{s}^2$.

Electrons are filled in orbitals in accordance with three rules: Aufbau principle, Hund’s rule, and Pauli’s exclusion principle. Aufbau principle states that electrons are filled in the orbitals from lower to higher energy level as follows:

  $1s<2s<2p<3s<3p<4s<3d<4p<5s<4d<5p<6s<4f<5d<6p<7s$

Hund’s rule states that initially each orbital is singly occupied and then pairing occurs and Pauli’s exclusion principle states that the spin of two electrons in one orbital is always different.

Answer to Problem 8.25QE

The electronic configuration of $\text{P}$ is $1s^{2}2s^{2}2p^{6}3s^{2}3p^3$.

Explanation of Solution

According to the location of $\text{P}$, its atomic number is 15. It is present in the nitrogen family of the periodic table. The number of electrons in $\text{P}$ is 15 and therefore its electronic configuration is $1s^{2}2s^{2}2p^{6}3s^{2}3p^3$.

(b)

Interpretation Introduction

Interpretation:

The electronic configuration of $\text{Sr}$ from its location in the periodic table has to be determined.

Concept Introduction:

Refer to part (a).

Answer to Problem 8.25QE

The electronic configuration of $\text{Sr}$ is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{6}5s^2$.

Explanation of Solution

According to the location of $\text{Sr}$ in the periodic table, its atomic number is 38. So it has 38 electrons in it and therefore its electronic configuration is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{6}5s^2$.

(c)

Interpretation Introduction

Interpretation:

The electronic configuration of $\text{Sm}$ from its location in the periodic table has to be determined.

Concept Introduction:

Refer to part (a).

Answer to Problem 8.25QE

The electronic configuration of $\text{Sm}$ is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}4d^{10}5s^{2}5p^{6}4f^{6}6s^2$.

Explanation of Solution

According to the location of $\text{Sm}$, its atomic number is 62. So it has 62 electrons in it and therefore its electronic configuration is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}4d^{10}5s^{2}5p^{6}4f^{6}6s^2$.

(d)

Interpretation Introduction

Interpretation:

The electronic configuration of $\text{Ra}$ from its location in the periodic table has to be determined.

Concept Introduction:

Refer to part (a).

Answer to Problem 8.25QE

The electronic configuration of $\text{Ra}$ is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d4s4p^{6}4d^{10}5s^{2}5p^{6}4f^{14}5d^{10}6s^{2}6p^{6}7s^2$.

Explanation of Solution

According to the location of $\text{Ra}$, its atomic number is 88. So it has 88 electrons in it and therefore its electronic configuration is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d4s4p^{6}4d^{10}5s^{2}5p^{6}4f^{14}5d^{10}6s^{2}6p^{6}7s^2$.