How many of the following are amphoteric oxides?
`Li_(2)O,Na_(2)O_(2),BeO,Al_(2)O_(3),MgO,BaO_(2)`

Answer

To determine how many of the given oxides are amphoteric, we need to analyze each oxide based on the definition of amphoteric oxides. Amphoteric oxides are those that can react with both acids and bases.

### Step-by-Step Solution:

1. **Identify the Oxides**: The oxides given in the question are:
- \( \text{Li}_2\text{O} \)
- \( \text{Na}_2\text{O}_2 \)
- \( \text{BeO} \)
- \( \text{Al}_2\text{O}_3 \)
- \( \text{MgO} \)
- \( \text{BaO}_2 \)

2. **Classify Each Oxide**:
- **\( \text{Li}_2\text{O} \)**: This is a basic oxide. It reacts with acids but not with bases.
- **\( \text{Na}_2\text{O}_2 \)**: This is also a basic oxide. It reacts with acids but not with bases.
- **\( \text{BeO} \)**: This is an amphoteric oxide. It can react with both acids and bases.
- **\( \text{Al}_2\text{O}_3 \)**: This is another amphoteric oxide. It can react with both acids and bases.
- **\( \text{MgO} \)**: This is a basic oxide. It reacts with acids but not with bases.
- **\( \text{BaO}_2 \)**: This is a basic oxide. It reacts with acids but not with bases.

3. **Count the Amphoteric Oxides**: From the classification:
- Amphoteric oxides: \( \text{BeO} \) and \( \text{Al}_2\text{O}_3 \) (2 in total).
- Basic oxides: \( \text{Li}_2\text{O} \), \( \text{Na}_2\text{O}_2 \), \( \text{MgO} \), and \( \text{BaO}_2 \) (4 in total).

4. **Conclusion**: Therefore, the number of amphoteric oxides among the given options is **2**.

### Final Answer:
**2 amphoteric oxides** (BeO and Al₂O₃).

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