Chapter 12, Problem 8A

(a)

Interpretation Introduction

Interpretation:

The most and least electronegative element among the given elements is to find out.

Concept introduction:

Electronegativity tells the power of an atom to attract pair of electrons which are shared between the atoms

Electronegativity increases in a period and decreases in the group.

Answer to Problem 8A

Most electronegative- $\mathrm{H}$

Least electronegative- $\mathrm{K}$

Explanation of Solution

$\mathrm{K}$ , $\mathrm{N}\mathrm{a}$ and $\mathrm{H}$ belongs to group-I and as one moves down the group, size increases and electronegativity decreases. Therefore, $\mathrm{H}$ is most electronegative and $\mathrm{K}$ is least electronegative.

(b)

Interpretation Introduction

Interpretation:

The most and least electronegative element among the given elements is to find out.

Concept introduction:

Electronegativity tells the power of an atom to attract pair of electrons which are shared between the atoms

Electronegativity increases in a period and decreases in the group.

Answer to Problem 8A

Most electronegative- $\mathrm{F}$

Least electronegative- $\mathrm{N}\mathrm{a}$

Explanation of Solution

$\mathrm{N}\mathrm{a}$ belongs to group-I and $\mathrm{F}$ and $\mathrm{B}\mathrm{r}$ belongs to group-17. As one move down the group, size increases and electronegativity decreases, and from left to right in a period, electronegativity increases. Therefore, $\mathrm{F}$ is most electronegative and $\mathrm{N}\mathrm{a}$ is least electronegative.

(b)

Interpretation Introduction

Interpretation:

The most and least electronegative element among the given elements is to find out.

Concept introduction:

Electronegativity tells the power of an atom to attract pair of electrons which are shared between the atoms

Electronegativity increases in a period and decreases in the group.

Answer to Problem 8A

Most electronegative- $\mathrm{F}$

Least electronegative- $\mathrm{B}$

Explanation of Solution

$\mathrm{B}$ , $\mathrm{N}$ and $\mathrm{F}$ belongs to period-II and as one moves from left to right in a period, size decreases and electronegativity increases. Therefore, $\mathrm{F}$ is most electronegative and $\mathrm{B}$ is least electronegative.