Which of the following elements does not show alltropy?

Options

A. Nitrogen
B. Bismuth
C. Antimony
D. Arsenic

Explanation

To determine which element does not show allotropy, we need to understand the concept of allotropy and analyze the elements in question.

### Step-by-Step Solution:

1. **Understanding Allotropy**:
- Allotropy is the phenomenon where an element can exist in two or more different forms in the same physical state. These different forms are called allotropes.

2. **Identifying Elements**:
- We need to consider the elements in question. Common examples of elements that exhibit allotropy include carbon (with forms like diamond and graphite), sulfur (with forms like rhombic and monoclinic), and phosphorus (with forms like white, red, and black phosphorus).

3. **Analyzing Nitrogen**:
- Among the elements, nitrogen is known to exist primarily as a diatomic molecule (N₂) in its most stable form. It does not have multiple stable allotropes in the same physical state like some other elements do.

4. **Weak N-N Bond**:
- The N-N bond in nitrogen is relatively weak, which limits its ability to form polymeric structures or multiple allotropes. This characteristic is a significant reason why nitrogen does not exhibit allotropy.

5. **Conclusion**:
- Based on the analysis, nitrogen is the element that does not show allotropy.

### Final Answer:
**Nitrogen does not show allotropy.**