Chapter 9, Problem 9.35QP

Interpretation Introduction

Interpretation:

Given the electronegativity values of atoms D, E, F and G, the molecules $DE,DG,EG$ and $DF$ have to be arranged in order of increasing covalent character.

Concept Introduction:

Ionic bond is the electrostatic force of attraction that binds ions of opposite charges into a stable molecule.  Electronegativity difference between the atoms must be greater than $1.7$ to form ionic bond between these atoms.

Covalent bond refers to the bond formed between two atoms by mutual sharing of electrons – that each atom shares equal number of electrons between them and the charge distribution (electron) between the two atoms held by covalent bond is symmetrical.  The difference in electronegativity between these two atoms is very less or the two atoms have same electronegativity.  Electronegativity difference between the atoms must be nil or highly lower than $1.7$ to form covalent bond between these atoms.

Polar covalent bond refers to the covalent bond which has polarity caused by unsymmetrical distribution of bonding electrons between the two atoms.  When atoms of moderately different electronegativity bonded by mutual sharing of electrons, the atom having more electronegativity tend to pull the electron cloud towards it.  This leads to unsymmetrical distribution of electrons between the bonded atoms that one end of the molecule develops slight positive charge and another end of the molecule develops slight negative charge.  This is called polarity and such bond is called polar covalent bond.

Electronegativity difference between the atoms must be $1.7$ or nearer to $1.7$ to form polar covalent bond between these atoms.