Chapter 4, Problem 4.93QP

Interpretation Introduction

Interpretation: In the given set of representation, the more realistic representation of an atom from group “2A” becoming an ion has to be identified.

Concept Introduction:

• An ion is formed by either loss or gain of electrons from its valence shell.
• An anion is formed when an electron is added to the valence shell of an atom.  The anion has a net negative charge in it.  In anion the extra electron added occupies more space and maximizes the shielding.
• A cation is formed when an electron is lost by an atom from its valence shell.  The cation has a net positive charge.  In cation the shielding decreases as the electron is removed from the valence shell.
• Metals tend to lose electrons to form cation and non-metals tend to gain electrons to form anion.
• Ionisation energy is the amount of energy required to remove an electron from the outermost orbital of an atom.  The trend in periodic table for ionization energy is, it increases across the period and decreases down the group.
• Electron affinity is the ability to attract the valence electron towards itself.  The trend in periodic table for ionization energy is, it increases across the period and decreases down the group.