Chapter 10, Problem 1SAQ

Which pair of elements has the most similar Lewis structures?

a. N and S

b. F and Ar

c. Cl and Ar

d. O and S

Interpretation Introduction

Interpretation: The pair of elements that would have the most similar structure is to be determined.

Concept Introduction:

Lewis structure is used to represent the molecules. It is also known as dot structure. In Lewis model, valence electrons are represented as dots.

Answer to Problem 1SAQ

Correct Answer: The most similar Lewis structure is of $\text{O}$ and $\text{S}$.

Therefore, the correct answer is option (d).

Explanation of Solution

Reason for correct option:

Oxygen $\left(\text{O}\right)$ and Sulfur $\left(\text{S}\right)$ both fall in the same group,$\text{6A}$. So, both have six valence electrons. Their Lewis structure can be represented as:

Thus, $\text{O}$ and $\text{S}$ have the most similar Lewis structure.

Hence, option (d) is correct.

Reasons for incorrect options:

Option (a) is given as $\text{N}$ and $\text{S}$.

Nitrogen falls in group $\text{5A}$ while Sulfur falls in group $\text{6A}$. So, their valence electrons are different. Nitrogen has five valence electrons and sulfur has six valence electrons. Hence, their Lewis structure would be different.

So, it is a wrong answer.

Option (b) is given as $\text{F}$ and $\text{Ar}$.

Fluorine falls in $\text{7A}$ while Argon falls in group $\text{8A}$. So, their valence electrons are different. Fluorine has seven valence electrons and argon has eight valence electrons. Hence, their Lewis structure would be different.

So, it is a wrong answer.

Option (c) is given as $\text{Cl}$ and $\text{Ar}$.

Chlorine falls in group $\text{7A}$ while Argon falls in group $\text{8A}$. So, their valence electrons are different. Chlorine has seven valence electrons and argon has eight valence electrons. Hence, their Lewis structure would be different.

So, it is a wrong answer.

Hence, options (a), (b) and (c) are incorrect.