Chapter 8, Problem 8.19QP

(a)

Interpretation Introduction

Interpretation: The element having 9 electrons has to be classified.

Concept Introduction:

• Electron configuration is the distribution of electrons in the atomic orbitals. It gives an idea about the shape and energy of electrons in an atom.
• The elements with same valence electrons have similar properties and are placed in the same group in periodic table.
• Group VII in the periodic table contains 7 valence electrons.
• The outer electronic configuration of halogens is ${\text{ns}}^{\text{2}}{\text{np}}^5$.

(b)

Interpretation Introduction

Interpretation: The element having 20 electrons has to be classified.

Concept Introduction:

• Electron configuration is the distribution of electrons in the atomic orbitals. It gives an idea about the shape and energy of electrons in an atom.
• The elements with same valence electrons have similar properties and are placed in the same group in periodic table.
• Group II in the periodic table contains 2 valence electrons.
• The outer electronic configuration of alkaline earth metal is ${\text{ns}}^{\text{2}}$.

(c)

Interpretation Introduction

Interpretation: The element having 26 electrons has to be classified

Concept Introduction:

• The elements in a periodic table can be classified into different categories according to the type of subshell containing the valence electrons, namely representative elements, transition metals the lanthanides, and the actinides.
• Transition elements contain either d subshell which are incomplete or that can form cations having incomplete d subshell.
• First-row transition metals have outer electronic configurations of ${\text{3d}}^{\text{(1-10)}}{\text{4s}}^{\left(\text{1-2}\right)}$. The 4s orbitals have lower energy comparing to the 3d orbitals and are filled first

(b)

Interpretation Introduction

Interpretation: The element having 33 electrons has to be classified.

Concept Introduction:

• Electron configuration is the distribution of electrons in the atomic orbitals. It gives an idea about the shape and energy of electrons in an atom.
• The elements with same valence electrons have similar properties and are placed in the same group in periodic table.
• Group V in the periodic table contains 5 valence electrons.
• The outer electronic configuration of Group 5A or 5 is ${\text{ns}}^{\text{2}}{\text{np}}^3$.