Zinc oxide is formed from the (Zn²
cation and the O²⁻
anion. What is the correct formula for this compound?
The Correct Answer and Explanation is:
Correct Formula:
The correct formula for zinc oxide is ZnO.
Explanation:
Zinc oxide is an ionic compound composed of a zinc cation (Zn²⁺) and an oxide anion (O²⁻). To determine the correct chemical formula of an ionic compound, we must balance the total positive and negative charges so that the overall compound is electrically neutral.
Zinc (Zn) is a transition metal, but it commonly forms only one stable ion: Zn²⁺. This means zinc typically loses two electrons to achieve a stable electron configuration, forming a cation with a 2+ charge.
Oxygen (O), on the other hand, is a nonmetal from group 16 of the periodic table. It typically gains two electrons to complete its octet, forming the oxide ion (O²⁻), which has a 2− charge.
Now, when combining ions to form an ionic compound, the total positive charge must equal the total negative charge. In this case:
- One Zn²⁺ ion contributes a +2 charge.
- One O²⁻ ion contributes a −2 charge.
Since the charges are equal in magnitude but opposite in sign, only one zinc ion and one oxide ion are needed to balance the charges. Therefore, the correct formula is ZnO, which reflects a 1:1 ratio of Zn²⁺ to O²⁻ ions.
This formula follows the basic principles of ionic compound formation:
- Identify the charges of the ions.
- Balance the total positive and negative charges.
- Write the formula with the lowest whole-number ratio of ions.
Thus, zinc oxide is represented by the formula ZnO, indicating it is made up of one zinc ion and one oxide ion bonded together in an ionic lattice structure.
