Chapter 10, Problem 44PE

(a)

Interpretation Introduction

Interpretation:

The complete electronic configuration of Selenium has to be given.

Concept Introduction:

Aufbau’s principle:

Aufbau’s principle states that electrons are filled into atomic orbitals in the increasing order of orbital energy level.  According to the Aufbau principle the available atomic orbitals with the lowest energy levels are occupied before those with higher energy levels.

Figure 1

(b)

Interpretation Introduction

Interpretation:

The shorthand electronic configuration of selenium has to be given.

(c)

Interpretation Introduction

Interpretation:

The number of valence electrons in selenium has to be given.

Concept Introduction:

Valence electrons:

Valence shell is the outermost shell of an every element.  Atom of every element has different electronic configurations based on the atomic number of each element.  Valence electrons are those electrons that located in the outermost shell surrounding an atomic nucleus.

Example: Sodium

The atomic number of sodium is $\text{11}\text{.}$

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

The outermost shell (valence shell) is $\text{3s}\text{.}$

The valence electron is one.

(d)

Interpretation Introduction

Interpretation:

The valence electrons in the shorthand electronic configuration have to be underlined.