The common valency shown by the elements of group 15 is/are

Options

A. `4`
B. `3,5`
C. `2,6`
D. `1,7`

Answer

To determine the common valency shown by the elements of Group 15, we need to analyze the electronic configurations and bonding behavior of the elements in this group, which includes nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi).

### Step-by-Step Solution:

1. **Identify the Elements of Group 15**:
- The elements in Group 15 are nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi).

2. **Determine the Electronic Configuration**:
- **Nitrogen (N)**: Atomic number = 7
- Electronic configuration: 1s² 2s² 2p³
- **Phosphorus (P)**: Atomic number = 15
- Electronic configuration: 1s² 2s² 2p⁶ 3s² 3p³
- **Arsenic (As)**: Atomic number = 33
- Electronic configuration: [Ar] 4s² 3d¹⁰ 4p³
- **Antimony (Sb)**: Atomic number = 51
- Electronic configuration: [Kr] 5s² 4d¹⁰ 5p³
- **Bismuth (Bi)**: Atomic number = 83
- Electronic configuration: [Xe] 6s² 4f¹⁴ 5d¹⁰ 6p³

3. **Analyze the Valency**:
- **Nitrogen**:
- Valence electrons = 5 (2s² 2p³)
- Can share 3 electrons to achieve a stable octet (valency = 3).
- **Phosphorus**:
- Valence electrons = 5 (3s² 3p³)
- Can share 3 electrons (valency = 3) or expand its octet to share 5 electrons (valency = 5).
- **Arsenic**:
- Similar to phosphorus, arsenic can also show valencies of 3 and 5.
- **Antimony**:
- Like arsenic, antimony can exhibit both valencies of 3 and 5.
- **Bismuth**:
- Primarily shows a valency of 3 due to the inert pair effect, but can also show 5 in some compounds.

4. **Conclusion**:
- The common valencies shown by the elements of Group 15 are both 3 and 5. Therefore, the answer is **both 3 and 5**.

### Final Answer:
The common valency shown by the elements of Group 15 is **both 3 and 5**.