Question

A pseudo solid is
A. Glass
B. Pitch
C. KCl
D. Glass and pitch both

Answer 1

Hint: Pseudo solids are those types of solids that may have physical appearance but they flow like liquids due to change in temperature. They have short range or order. They are also known as super cooled liquids and amorphous solids.

Complete step-by-step answer:
Pseudo solids are those types of solids which have appearance as solid but still they act like liquid like they have a tendency to flow which is quite slow and it is so slow that you can’t observe it with naked eye. You can also say that it has high viscosity. Glass and pitch are examples of pseudo solids.
Glass gets thicker at bottoms and thinner at top due to change in environmental conditions. Similarly pitch is a viscoelastic polymer which may be made naturally and artificially like tar, asphalt. Pitch appears to be solids but they can flow at extremely slow rates. Therefore, pitch is also the type of pseudo solid.
KCl is the type of crystalline solid as it has long range order, definite geometrical pattern and is anisotropic in nature. The correct answer is D.

Note: Pseudo solids are the short-range order solids that are isotropic in nature due to which they have different physical properties in different directions and they have melting point in the range of temperature unlike crystalline that have fixed melting point.
They don’t have any definite geometrical pattern like crystalline structures. All amorphous solids are pseudo solids. Glass and pitch are pseudo solids.