Question

Which among the following can be categorized into a pseudo solid?

• A. $Ca{F}_2\left(s\right)$
• B. Glass
• C. $NaCl\left(s\right)$
• D. All of the above

Answer 1

The correct option is B Glass

Amorphous solids are formed by sudden cooling of a liquid. These solids are sometimes called as supercooled liquid or pseudo solids because they possesses the property of liquids.
Glass is prepared by sudden cooling of molten glass. Glass is a pseudo solid and in a very slow process, it flows like a liquid due to which the base of glass windows gets thicker than at top.

$Ca{F}_2$ and $NaCl$ are crystalline solids. They comes under the category of crystalline solids since they have a 3D arrangement of cation and anions in a ordered way and have a well defined regular shapes.

Thus, glass or quartz glass is a pseudo solid or super cooled liquid.