Chapter 6, Problem 78A

Interpretation Introduction

(a)

Interpretation:

The more electronegative element from the pair needs to be determined.

K, As.

Concept introduction:

Electronegative elements are those which will accept electrons. In a group, electro negativity decreases from top to bottom as atomic size raises and the valence electrons are far away from the nucleus leading to smaller nuclear charge. It increases across the period in the periodic table as the atomic size decreases and the valence electrons are closer to the nucleus leading to more nuclear charge.

Answer to Problem 78A

The more electronegative element from pair K and As is As.

Explanation of Solution

As and K both are elements of period 4 but As (Arsenic) lies to the right of K (potassium). In a period, electro negativity increases from left to right. Therefore, As is more electronegative compared to K.

(b)

Interpretation Introduction

Interpretation:

The atom which is more electronegative element from the pair needs to be determined.

N, Sb.

Concept introduction:

Electronegative elements are those which will accept electrons. In a group, electro negativity decreases from top to bottom as atomic size raises and the valence electrons are far away from the nucleus leading to smaller nuclear charge. It increases across the period in the periodic table as the atomic size decreases and the valence electrons are closer to the nucleus leading to more nuclear charge.

Answer to Problem 78A

The more electronegative element is N.

Explanation of Solution

Nitrogen and antimony both are the elements of same group (group 15) but nitrogen is found above the Sb. As electro negativity decreases down the group, therefore, N is more electronegative than Sb.

(c)

Interpretation Introduction

Interpretation:

The electronegative element from the pair needs to be determined.

Sr, Be.

Concept introduction:

Electronegative elements are those which will accept electrons. In a group, electro negativity decreases from top to bottom as atomic size raises and the valence electrons are far away from the nucleus leading to smaller nuclear charge. It increases across the period in the periodic table as the atomic size decreases and the valence electrons are closer to the nucleus leading to more nuclear charge.

Answer to Problem 78A

The more electronegative element from pair Sr and Be is Be.

Explanation of Solution

Strontium (Sr) and beryllium (Be) both are the element of same group (2A) but beryllium is found above the Sr. As electro negativity decreases down the group, therefore, Be is more electronegative than Sr.