Question

Which of the following is amorphous?
A. Sodium chloride
B. Quartz glass
C. Powdered marble
D. Cane sugar

Answer 1

In this question, as we have to tell which of the following compounds is amorphous. So amorphous solids have no specific shapes and they are lacking their definite form; they are formless. They are having no pattern or structure. They are lacking a clear structure or focus and they have no particular kind of character.

Complete step by step answer:
Firstly, amorphous is defined as a substance which is lacking in clear structure or shape. That solids which do not have any underlying order in their molecular structure. On the other hand crystalline solid or the crystal is defined as those solids that have a well defined order in their structure.
Moreover, that solid material whose constituents are arranged in a highly ordered microscopic structure which further forms a crystal lattice that extends in all the directions.
Talking about quartz glass, it is an amorphous solid because it is formed by the fusing crystal and after that cooling it very rapidly. Furthermore, crystalline solids have regular ordered components which are held together by uniform intermolecular forces, whereas the components of amorphous solids are not arranged in a regular way.
As we learnt previously, there are three states of matter namely, solids, liquids and gases. Solids have two states namely amorphous crystalline form. In crystalline solids, the particles are arranged in a three dimensional order. These particles have equal intermolecular forces. They are called true solids. Examples of crystalline solids are benzoic acid and diamond. Moreover, it is widely used in making beautiful jewellery.
Whereas amorphous solids are shapeless. They have irregular arrangement of solid particles. Their intermolecular forces are not equal. They have undefined geometric shape. They are also called a supercooled liquid. Examples of amorphous solids are naphthalene and glass. Even more, these solids are widely used in the construction of buildings.

So, the correct answer is Option B

Note: Quartz glass is an extremely versatile material which is used in a range of different applications. The chemical formula is $Si{O_2}$. It has very outstanding thermal properties, good electrical and corrosion performance. Moreover glass has a random molecular structure while quartz has a symmetrical molecular structure. But both quartz and glass are utilized for electrical purposes.