Chapter 18.2, Problem 13R

To determine

To show:the sum of the positive and negative charges in a unit of ${\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}$ equals to zero.

Explanation of Solution

Given:

The compound is aluminum oxide $\left({\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\right)$ .

Calculation:

  ${\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}$ possess aluminum and oxygen. Aluminum belongs to group 13 of the periodic table and oxygen belongs to the group of 16. Aluminum has 3 electrons in its outermost shell and it loses 3 electrons to form ${\text{Al}}^{\text{+3}}$ ion. Similarly, oxygen is having 6 electrons in its outermost shell and gains 2 electrons to form ${\text{O}}^{\text{-2}}$ ion.

Aluminum is having +3 charges and is multiplied by 2 then the total charge will be +6.

Oxygen is having -2 charges and is multiplied by +3 then the total charge will become -6.

Thus, aluminum has +6 charges and oxygen has -6 charges. After the addition of total charge of oxygen and aluminum, the net charge equals to zero.

Conclusion:

Thus, the sum of charge on aluminum and oxygen is equal to zero.