Select the correct statement about elements of group 15th.

Options

A. The order or stability of oxidation state for `+3` is `Bi^(3+) gt Sb^(3+) gt As^(3+)` and for `+5` is `Bi^(5+) lt Sb^(5+) lt As^(5+)`
B. In the case on nitrogen, all oxiation states from `+1" to "+4` tend to disproportioanate in acid solution.
C. There is considerale in covalent radius from N to P but from As to Bi only a small increase in covalent radius is observed.
D. All of these

Answer

To solve the question regarding the correct statement about elements of group 15, we will analyze the properties and oxidation states of these elements step by step.

### Step 1: Identify the Elements of Group 15
Group 15 of the periodic table consists of the following elements:
- Nitrogen (N)
- Phosphorus (P)
- Arsenic (As)
- Antimony (Sb)
- Bismuth (Bi)

### Step 2: Understand the Common Oxidation States
The common oxidation states for elements in group 15 are +3 and +5. This is due to their general electron configuration of ns²np³, where 'n' represents the principal quantum number.

- **+3 Oxidation State**: This occurs when three electrons are removed from the outer shell.
- **+5 Oxidation State**: This occurs when five electrons are removed from the outer shell.

### Step 3: Stability of Oxidation States
As we move down the group from nitrogen to bismuth, the stability of the oxidation states changes:
- The +5 oxidation state is generally more stable for lighter elements (like nitrogen and phosphorus).
- However, for heavier elements like bismuth, the +3 oxidation state becomes more stable due to the **inert pair effect**. This effect arises because the s-electrons (in the outermost shell) are less available for bonding due to increased shielding from inner d and f electrons.

### Step 4: Analyze the Inert Pair Effect
The inert pair effect refers to the tendency of the two s-electrons to remain non-bonding in heavier elements. As we move down the group:
- The inert pair effect increases, making the +3 oxidation state more stable compared to the +5 oxidation state for heavier elements (like Bi).

### Step 5: Examine the Oxidation State Variability
Nitrogen can exhibit a wide range of oxidation states from -3 to +5. This includes:
- Disproportionation reactions, where nitrogen can change from one oxidation state to another (e.g., from +1 to -3 or +5).

### Step 6: Covalent Radius Consideration
There is a considerable increase in covalent radius from nitrogen to bismuth. However, the increase in covalent radius from arsenic (As) to bismuth (Bi) is less pronounced due to d-block and f-block contractions.

### Conclusion
Based on the analysis, the correct statements regarding group 15 elements are:
1. The +3 oxidation state becomes more stable than the +5 oxidation state as you move down the group due to the inert pair effect.
2. Nitrogen can exhibit oxidation states from -3 to +5, allowing for disproportionation.
3. There is a considerable increase in covalent radius from nitrogen to bismuth, but the increase from arsenic to bismuth is smaller due to d-block contraction.

### Final Answer
All of the statements regarding the elements of group 15 are correct.

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