Question

Which of the following crystal is represented by $a\ne b\ne c\text{and}\alpha =\beta =\gamma ={90}^{\circ }$?
[0.77 Mark]

• A. Tetragonal
• B. Cubic
• C. Orthorhombic
• D. Trigonal

Answer 1

The correct option is C Orthorhombic

• For tetragonal, parameters of unit cell, $\to a=b\ne cand\alpha =\beta =\gamma ={90}^{\circ }$
• For cubic, parameters of unit cell, $\to a=b=cand\alpha =\beta =\gamma ={90}^{\circ }$
• For orthorhombic, parameters of unit cell, ~ $\to a\ne b\ne cand\alpha =\beta =\gamma ={90}^{\circ }$
• For trigonal, parameters of unit cell, $\to a=b=cand\alpha =\beta =\gamma \ne {90}^{\circ }$