Chapter 7, Problem 30A

Interpretation Introduction

Interpretation: To determine the two ways through which ions can be formed from an atom.

Concept Introduction: When atoms lose are gain their electrons, then they will form their ions. It may cation and anion.

Answer to Problem 30A

Ions can be formed in two ways and they are:

• By losing electrons (cation)
• By gaining electrons (anion)

Explanation of Solution

Atoms lose or gain electrons to create ions. All atoms aim to have a complete octet of electrons. Atoms having seven valence electrons would want to add one more so that they have more have eight in total. It's simpler to gain one rather than to lose seven.

1. An anion will form when an atom will gain electrons. For example, a Chlorine atom gains one electron and forms an anion. $\text{Cl+e}\to {\text{Cl}}^{-}$
2. Cations will form by losing electrons. For example, an aluminum atom loses its three electrons and can form a cation. $\text{Al}\text{-}{\text{3e}}^{\text{-}}\to {\text{Al}}^{\text{3+}}$