Chapter 21, Problem 7PS

Interpretation Introduction

Interpretation: Give the name and symbol of elements having the valence configuration $\left[\text{noble gas}\right]{\text{ns}}^{\text{2}}{\text{np}}^{\text{1}}$.

Concept introduction: Noble gases are group of elements with very low chemical reactivity. The six noble gas elements that have been isolated are:

• Helium
• Neon
• Argon
• Krypton
• Xenon
• Radon

The atomic number of Helium is $2$ and symbol is $\text{He}$, Neon is $10$ and symbol is $\text{Ne}$, Argon is $18$ and symbol is $\text{Ar}$, Krypton is $36$ and symbol is $\text{Kr}$, Xenon is $54$ and symbol is $\text{Xe}$, Radon is $86$ and symbol is $\text{Rn}$.

The elements having the electronic configuration of $\left[\text{noble gas}\right]{\text{ns}}^{\text{2}}{\text{np}}^1$ have three valence electrons in their outermost shell. Such elements belong to group $\text{3A}$ of periodic table and lose these three electrons to gain noble gas configuration. Group $\text{3A}$ is boron family and the other elements of this group are aluminium, gallium, indium and thallium.