The most common oxidation states of 3d series elements

Options

A. `+2`
B. `+3`
C. `+4`
D. `+7`

Answer

To determine the most common oxidation states of the 3d series elements (atomic numbers 21 to 30), we will analyze each element in this series and identify their oxidation states based on their electronic configurations.

### Step-by-Step Solution:

1. **Identify the Elements**: The 3d series elements include Scandium (Sc, 21), Titanium (Ti, 22), Vanadium (V, 23), Chromium (Cr, 24), Manganese (Mn, 25), Iron (Fe, 26), Cobalt (Co, 27), Nickel (Ni, 28), Copper (Cu, 29), and Zinc (Zn, 30).

2. **Write the Electronic Configurations**:
- Sc: [Ar] 3d¹ 4s²
- Ti: [Ar] 3d² 4s²
- V: [Ar] 3d³ 4s²
- Cr: [Ar] 3d⁵ 4s¹
- Mn: [Ar] 3d⁵ 4s²
- Fe: [Ar] 3d⁶ 4s²
- Co: [Ar] 3d⁷ 4s²
- Ni: [Ar] 3d⁸ 4s²
- Cu: [Ar] 3d¹⁰ 4s¹
- Zn: [Ar] 3d¹⁰ 4s²

3. **Determine Possible Oxidation States**:
- **Scandium (Sc)**: +2 (removing 2 electrons from 4s) or +3 (removing 3 electrons from 4s and 3d).
- **Titanium (Ti)**: +2, +3, +4.
- **Vanadium (V)**: +2, +3, +4, +5.
- **Chromium (Cr)**: +2, +3, +4, +5, +6.
- **Manganese (Mn)**: +2, +3, +4, +5, +6, +7.
- **Iron (Fe)**: +2, +3, +4, +5, +6.
- **Cobalt (Co)**: +2, +3, +4.
- **Nickel (Ni)**: +2, +3.
- **Copper (Cu)**: +1, +2.
- **Zinc (Zn)**: +2 (only).

4. **Analyze the Common Oxidation States**:
- From the analysis, we can see that the oxidation states +2 and +3 are prevalent across most of the 3d series elements.
- The oxidation state +2 is especially common as it appears in Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn.
- The oxidation state +3 is also common but is not present in all elements (e.g., Zn only shows +2).

5. **Conclusion**: The most common oxidation states of the 3d series elements are +2 and +3, but since +2 appears in all elements except for copper (which has +1 and +2), we can conclude that the most common oxidation state across the entire series is +2.

### Final Answer:
The most common oxidation state of the 3d series elements is **+2**.

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