Chapter 22, Problem 22.93SP

Interpretation Introduction

Interpretation:

“Explain why the properties of boron differ so markedly from the properties of the other group 3 A elements.” should be explained

Concept introduction:

• Group 3A or 13: The elements of this group 13 are also known as boron family. The elements of this group are following:

  $\begin{array}{l}\text{Elements Electronic configuration (}n{s}^{2}n{p}^1\text{)}\\ \text{Boron (B) 2}{s}^{2}2p^1\\ \text{Aluminum (Al) 3}{s}^{2}3p^1\\ \text{Gallium (Ga) 4}{s}^{2}4p^1\\ \text{Indium (In) 5}{s}^{2}5p^1\\ \text{Thallium (Tl) 6}{s}^{2}6p^1\\ \text{Ununtrium (Uut) 7}{s}^{2}7p^1\end{array}$

• Ionization energy is the energy required to remove an electron from a gaseous atom or ion. Generally as we go across a period from left to right, the first ionization energy increases, on the other hand first ionization energy decrease in going down a group.
• Atomic radius decreases in going from left to right across a period. This decrease can be explained in term of the increasing effective nuclear charge in going from left to right. This means that the valence electrons are down closer to the nucleus, decreasing the size of atom. Atomic radius increases down a group, because of the increases in the orbital sizes in successive principal quantum levels.