Question:
The parameters of the unit cell of a substance are $\mathrm{a}=2.5, \mathrm{~b}=3.0, \mathrm{c}=4.0, \alpha=90^{\circ}, \beta=120^{\circ} \gamma=90^{\circ}$. The crystal system of the substance is :
Correct Option: , 3
Solution:
$\mathrm{a} \neq \mathrm{b} \neq \mathrm{c}$ and $\alpha=\gamma=90^{\circ} \neq \beta$
are parameters of monoclinic unit cell.