Chapter 4, Problem 4.88MP

(a)

Interpretation Introduction

Interpretation:

Electron-dot structures for $\text{OH}$ molecule and ${\text{OH}}^{-}$ ion has to be drawn.

Concept introduction:

Electron-dot structure:

This is only way to show the sharing of electrons between atom in polar covalent bonds or covalent bond.  This is often called Lewis structure.  This structure denotes valence electrons of an atom by dots and also it shows the way of valence electron distributed within a molecule.

(b)

Interpretation Introduction

Interpretation:

Electron added to $\text{OH}$ is localised in a single atomic orbital on one atom.  The atom accepting the electron has to be identified and n and l quantum numbers of atomic orbital has to be given.

Concept introduction:

Principle quantum number (n):

The principle quantum number specifies the main energy level which is occupied by an electron.

$\text{n =1, 2, 3 and so on}$.

For example, $\text{n =1}$ means electron occupies first level.

Angular momentum quantum number (l):

Angular momentum quantum number denotes the shape of the orbital of an atom.

The number of shape of the orbital possible is equal to n for definite main energy level. The allowed values are zero to $\left(\text{n-1}\right)$.

(c)

Interpretation Introduction

Interpretation:

Electron affinity of $\text{OH}$ is slightly more negative than that of Oxygen atom.  This has to be explained.

Concept introduction:

Electron affinity:

Electron affinity is amount of energy released when electron is added to an atom.  In the periodic table electron affinity increases from left to right and decreases from top to bottom.