Which of the following crystal is represented by `a ne b ne c` and `alpha ne beta ne gamma ne 90^(@)` ?

Options

A. Orthorhombic
B. Monoclinic
C. Triclinic
D. Tetragonal

Answer

To solve the question regarding the type of crystal represented by the conditions `a ≠ b ≠ c` and `α ≠ β ≠ γ ≠ 90°`, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Given Conditions**:
- We have three edge lengths: `a`, `b`, and `c`.
- We have three angles: `α`, `β`, and `γ`.
- The conditions state that all edge lengths are unequal (`a ≠ b ≠ c`) and all angles are also unequal (`α ≠ β ≠ γ`) and not equal to 90°.

2. **Identify the Crystal Systems**:
- Crystals can be classified into several systems based on their edge lengths and angles:
- **Cubic**: `a = b = c` and `α = β = γ = 90°`
- **Tetragonal**: `a = b ≠ c` and `α = β = γ = 90°`
- **Orthorhombic**: `a ≠ b ≠ c` and `α = β = γ = 90°`
- **Monoclinic**: `a ≠ b ≠ c`, `α = γ = 90°`, and `β ≠ 90°`
- **Triclinic**: `a ≠ b ≠ c` and `α ≠ β ≠ γ` and none equal to 90°.

3. **Analyze the Conditions**:
- The conditions `a ≠ b ≠ c` eliminate cubic, tetragonal, and orthorhombic systems.
- The condition `α ≠ β ≠ γ` and none equal to 90° eliminates monoclinic as well.

4. **Conclusion**:
- The only crystal system that fits all the given conditions is the **Triclinic** system, where all edges are unequal and all angles are also unequal and not equal to 90°.

### Final Answer:
The crystal represented by the conditions `a ≠ b ≠ c` and `α ≠ β ≠ γ ≠ 90°` is **Triclinic**.

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