The most common oxidation state exhibited by the d-block elements (and why) in the 3d series is

Options

A. `+3`, due to the participation of ns and np electrons
B. ` +3`, due to the participation of ns and (n – 1)d- electrons
C. `+2`, due to the participation of ns electrons
D. ` +2`, due to the participation of (n – 1)d unpaired electrons

Answer

To determine the most common oxidation state exhibited by the d-block elements in the 3d series, we can follow these steps:

### Step 1: Identify the Elements in the 3d Series
The 3d series of transition metals includes the following elements:
- Scandium (Sc)
- Titanium (Ti)
- Vanadium (V)
- Chromium (Cr)
- Manganese (Mn)
- Iron (Fe)
- Cobalt (Co)
- Nickel (Ni)
- Copper (Cu)
- Zinc (Zn)

### Step 2: Write the Outermost Electronic Configurations
The outermost electronic configurations for these elements are:
- 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

### Step 3: Determine Possible Oxidation States
The oxidation states can be derived from the loss of electrons from the outermost shell:
- Sc: +2 (from 4s) or +3 (from 3d)
- Ti: +2, +3, +4
- V: +2, +3, +4, +5
- Cr: +1, +2, +3, +4, +5, +6
- Mn: +2, +3, +4, +5, +6, +7
- Fe: +2, +3, +4, +5, +6
- Co: +2, +3, +4
- Ni: +2, +3, +4
- Cu: +1, +2
- Zn: +2

### Step 4: Identify the Most Common Oxidation State
From the above possible oxidation states, the most common oxidation state across the 3d series is +2. This is because:
- The +2 oxidation state is achieved by losing the two 4s electrons, which are the outermost electrons in these transition metals.

### Step 5: Conclusion
The most common oxidation state exhibited by the d-block elements in the 3d series is +2 due to the loss of the two 4s electrons.

---