Which of the following statement is correct for 3d-transition element

Options

A. All the metals except Sc forms 'MO' oxide
B. All the metals except Zn forms 'MO' oxide
C. All the metals except Zn and Sc form 'MO' oxide
D. All the metals except Mn forms 'MO' oxide

Answer

To determine which statement is correct for 3d-transition elements regarding their ability to form MO oxides, we will analyze the oxidation states of each element in the 3d series and their corresponding oxides.

### Step 1: Identify the 3d Transition Elements
The 3d transition elements include:
- Scandium (Sc)
- Titanium (Ti)
- Vanadium (V)
- Chromium (Cr)
- Manganese (Mn)
- Iron (Fe)
- Cobalt (Co)
- Nickel (Ni)
- Copper (Cu)
- Zinc (Zn)

### Step 2: Understand the Oxidation States
For the formation of MO oxides, the metal (M) must be in the +2 oxidation state (M²⁺). We will check which elements can stably exist in this oxidation state.

1. **Scandium (Sc)**: Typically forms +3 oxidation state (Sc³⁺), +2 is rare and unstable.
2. **Titanium (Ti)**: Can form +2 (Ti²⁺), +3, and +4 states.
3. **Vanadium (V)**: Can form +2 (V²⁺), +3, +4, and +5 states.
4. **Chromium (Cr)**: Can form +2 (Cr²⁺), +3, +4, +5, and +6 states.
5. **Manganese (Mn)**: Can form +2 (Mn²⁺), +3, +4, +5, +6, and +7 states.
6. **Iron (Fe)**: Can form +2 (Fe²⁺) and +3 states.
7. **Cobalt (Co)**: Can form +2 (Co²⁺) and +3 states.
8. **Nickel (Ni)**: Can form +2 (Ni²⁺) and +3 states.
9. **Copper (Cu)**: Can form +1 (Cu⁺) and +2 states.
10. **Zinc (Zn)**: Only forms +2 (Zn²⁺) state.

### Step 3: Analyze the Options
Now, let's analyze the options provided:

- **Option A**: All metals except scandium form MO oxide.
- **True**: All other metals can stably exist in the +2 oxidation state and can form MO oxides.

- **Option B**: All metals except zinc form MO oxide.
- **False**: Zinc can form ZnO as it exists in the +2 oxidation state.

- **Option C**: All metals except zinc and scandium form MO oxide.
- **False**: Again, zinc can form ZnO.

- **Option D**: All metals except Mn form MO oxide.
- **False**: Manganese can form MnO.

### Conclusion
The correct statement is **Option A**: All metals except scandium form MO oxide.

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