Question

For the orthorhombic system, axial ratios are $a\ne b\ne c$ and the axial angles are:

• A. $\alpha =\beta =\gamma \ne {90}^0$
• B. $\alpha =\beta =\gamma ={90}^0$
• C. $\alpha =\gamma ={90}^0,\beta \ne {90}^0$
• D. $\alpha \ne \beta \ne \gamma ={90}^0$

Answer 1

The correct option is B

$\alpha =\beta =\gamma ={90}^0$

Orthorhombic crystal has three unequal axes which are at a right angle to each other. In the orthorhombic crystal system, all the edge lengths a, b and c are not the same, but all angles are equal i.e. ${90}^0$.

Hence option B is correct