Question

Which one of the following is non-crystalline

(a) Diamond

(b) Graphite

(c) Glass

(d) Common Salt​

Answer 1

Among the given substances, the non-crystalline substance is glass. Thus, the correct option is (c).

Explanation:

• Diamond is a three-dimensional crystalline and anisotropic substance. It has a regular arrangement of atoms in its crystal structure.
• Graphite is a two-dimensional crystalline substance. It also has a regular arrangement of atoms.
• Common salt ($NaCl$) is also a crystalline substance. The ions in common salt are arranged in the fcc lattice structure.
• On the other hand, glass is an amorphous solid substance. It consists of a random or irregular arrangement of atoms throughout the solid.
• Thus, glass is non-crystalline.