Example of an amphoteric oxide is

Options

A. a.`Na_(2)O`
B. b.`MgO`
C. c.`Al_(2)O_(3)`
D. d.`CaO`

Explanation

To determine an example of an amphoteric oxide, we need to first understand what an amphoteric oxide is. Amphoteric oxides are substances that can react with both acids and bases to form salts and water.

### Step-by-Step Solution:

1. **Definition of Amphoteric Oxide**:
- An amphoteric oxide is defined as an oxide that can react with both acids and bases. This means it can neutralize both types of substances.

2. **Identifying the Options**:
- The options provided are:
- A) Sodium oxide (Na2O)
- B) Magnesium oxide (MgO)
- C) Aluminum oxide (Al2O3)
- D) Calcium oxide (CaO)

3. **Analyzing Each Option**:
- **Sodium Oxide (Na2O)**: This oxide primarily reacts with acids and does not exhibit amphoteric behavior.
- **Magnesium Oxide (MgO)**: This oxide is basic and reacts mainly with acids, not bases.
- **Aluminum Oxide (Al2O3)**: This oxide can react with both acids and bases. For example:
- When reacting with hydrochloric acid (HCl):
\[ \text{Al}_2\text{O}_3 + 6 \text{HCl} \rightarrow 2 \text{AlCl}_3 + 3 \text{H}_2\text{O} \]
- When reacting with sodium hydroxide (NaOH):
\[ \text{Al}_2\text{O}_3 + 2 \text{NaOH} + 3 \text{H}_2\text{O} \rightarrow 2 \text{NaAl(OH)}_4 \]
- **Calcium Oxide (CaO)**: This oxide is also basic and primarily reacts with acids.

4. **Conclusion**:
- From the analysis, we can conclude that **Aluminum oxide (Al2O3)** is the only oxide that exhibits amphoteric behavior, as it reacts with both acids and bases.

### Final Answer:
The example of an amphoteric oxide is **C) Aluminum oxide (Al2O3)**.