Which of the following elements form amphoteric oxides?
`Be, B, Al, Ga, Sn, Zn, Ge, Cu, Mn` 

Answer

To determine which of the given elements form amphoteric oxides, we will analyze each element based on their chemical properties. Amphoteric oxides are those that can react with both acids and bases, forming salts and water.

### Step-by-Step Solution:

1. **Understand Amphoteric Oxides**:
- Amphoteric oxides can react with both acids and bases. This means they can behave as either an acid or a base depending on the reaction conditions.

2. **List the Elements**:
- The elements given are: Be (Beryllium), B (Boron), Al (Aluminium), Ga (Gallium), Sn (Tin), Zn (Zinc), Ge (Germanium), Cu (Copper), Mn (Manganese).

3. **Identify Amphoteric Oxides**:
- **Beryllium (BeO)**: Beryllium oxide is amphoteric.
- **Boron (B2O3)**: Boron oxide can behave amphoterically under certain conditions, but is primarily acidic.
- **Aluminium (Al2O3)**: Aluminium oxide is amphoteric.
- **Gallium (Ga2O3)**: Gallium oxide is amphoteric.
- **Tin (SnO)**: Tin oxide can show amphoteric behavior.
- **Zinc (ZnO)**: Zinc oxide is amphoteric.
- **Germanium (GeO)**: Germanium oxide can be amphoteric.
- **Copper (CuO)**: Copper oxide is generally considered basic.
- **Manganese (MnO)**: Manganese oxides are typically basic.

4. **Compile the Results**:
- The elements that form amphoteric oxides from the list are: Be, Al, Ga, Sn, Zn, and Ge.

5. **Final Answer**:
- The elements that form amphoteric oxides are: **Be, Al, Ga, Sn, Zn, Ge**.