Question

The lattice parameters, $a\ne b\ne c$ and $\alpha =\gamma ={90}^{\circ },\beta \ne {90}^{\circ }$ represents a :

• A. tetragonal system
• B. orthorhombic system
• C. monoclinic system
• D. triclinic system

Answer 1

Answer: (C)

monoclinic system

The axial distances and the axial angles, $a\ne b\ne c$ and $\alpha =\gamma ={90}^{\circ },\beta \ne {90}^{\circ }$ represents a monoclinic system.

None of the edge lengths is equal to each other.

Two of the angles are equal to each other and equal to ${90}^0$. One of the angles is not equal to ${90}^0$.

Example of triclinic crystal systems is $N{a}_{2}S{O}_4.10H_{2}O$.

Hence, the correct option is $\text{C}$