Chapter 4, Problem 4.61QP

Interpretation Introduction

Interpretation: Alkali metals have more electron affinity than alkaline earth metals has to be explained.

Concept Introduction:

• When an electron is added to an atom in gaseous phase, energy is released by the atom.  This amount of energy released is known as electron affinity. A neutral atom is converted to anion when an electron is added.  If the electron affinity value is positive, the atom of that element can accept an electron easily and if it is negative, the atom cannot accept the electron.  Ionization energy and electron affinity are related directly.
• The trend of electron affinity in periodic table is that, it increases across the period and decreases down the period.  This is because when we move across the period, the electrons are added to the same sub-shell, but when moving down the group, electrons are added to a new sub-shell.
• Noble gas has the lowest electron affinity and halogens have the largest electron affinity.

To explain: why alkali metals have more electron affinity than alkaline earth metals.