Monoclinic sulphur is an example of monoclinic crystal system. What are the characteristics of the crystal system?

• A

  $\mathrm{a}\ne \mathrm{b}\ne \mathrm{c},\mathrm{\alpha }=\mathrm{\beta }=\mathrm{\gamma }=90°$
• B

  $\mathrm{a}\ne \mathrm{b}\ne \mathrm{c},\mathrm{\alpha }\ne \mathrm{\beta }\ne \mathrm{\gamma }\ne 90°$
• C

  $\mathrm{a}=\mathrm{b}\ne \mathrm{c},\mathrm{\alpha }=\mathrm{\beta }=\mathrm{\gamma }=90°$
• Correct answer
  D

  $\mathrm{a}\ne \mathrm{b}\ne \mathrm{c},\mathrm{\alpha }=\mathrm{\gamma }=90°,\mathrm{\beta }\ne 90°$

Solution

For monoclinic crystal system,
$\mathrm{a}\ne \mathrm{b}\ne \mathrm{c},\mathrm{\alpha }=\mathrm{\gamma }=90°,\mathrm{\beta }\ne 90°$

Hence, the correct answer is option: 'D'.