Question

Which of the following is an amorphous solid?

• A. Graphite
• B. Quartz glass
• C. Chrome alum
• D. Silicon carbide

Answer 1

The correct option is B

Quartz glass

Explanation for correct option:

B. Quartz glass

Solids can be classified into two categories on the basis of the nature of order present in the arrangement of their constituent particles.

Crystalline solid:

• “A crystalline solid usually consists of a large number of small crystals, each of them having a definite characteristic geometrical shape.”
• “In a crystal, the arrangement of constituent particles (atoms, molecules or ions) is ordered.”
• Examples of crystalline solids are Sodium chloride and quartz.

Amorphous solid:

• “An amorphous solid (Greek amorphos = no form) consists of particles of irregular shape.”
• “The arrangement of constituent particles (atoms, molecules or ions) in such a solid has only short-range order.”
• Examples of amorphous solids are Glass. rubber as well as Plastics.

Thus, option B i.e. Quartz glass is an amorphous solid.

Explanation for incorrect options:

A: Graphite is a covalent network type solid(Covalent network solids are composed of atoms covalently bonded together into a three-dimensional network or layers of two-dimensional networks).

C: Chrome alum is a crystalline solid.

D: Silicon carbide is a covalent network solid.

Hence, the correct option is B i.e. Quartz glass.