Chapter 7, Problem 80SCQ

Interpretation Introduction

Interpretation:

The chemical reaction of Calcium (Ca) and fluorine (F) does not form Calcium fluoride (CaF₃); the reason has to be explained.

Concept Introduction:

Ionization energy (IE): The ionization energy is the required to remove an electron from an atom in the gas phase.

General formula of ionization energy= $\begin{array}{l}\text{Atom in the ground state(g)}\to {\text{Atom}}^{\text{+}}(g)+e^{-}\\ \text{ΔU=}\text{Ionization}\text{energy}\text{(IE)}\end{array}$

As predicted by coulomb’s law, energy must be supplied to overcome the attraction between an electron and the nucleus and to separate the electron from the atom. Thus ionization energies always have positive values. An electron father from the nucleus generally has smaller ionization energy and electron closer to the nucleus has larger ionization energy. 

Increase and decrease electro negativity: The less vacancy electrons an atoms has the least it will gain of electrons. Moreover the electron affinity decrease down the groups and from right to left across the periods on the periodic table, the reason is electrons are placed in a higher energy level far from the nucleus thus a decrease from its pull.