Question

Statement-I: Initially the term pseudo solid was given for solids which were easily distorted by bending and compression forces. They even tend to flow slowly under their own weight and lose shape.
Statement-II: These characteristics are shown by pseudo solids as in pitch, glass and thus, the name pseudo solid was replaced by supercooled liquids.
A. I is correct but II is wrong
B. I is wrong but II is correct
C. Both I and II are correct and II is correct explanation of I
D. Both I and II are correct but II is not correct explanation of I

Answer 1

Amorphous solids like glass are examples of pseudo solids and it is observed to show liquid-like flow properties on a longer time scale than compared to liquids under influence of physical forces, generally, its own weight.

Complete step by step answer: We have been provided with two statements to judge them for their correctness and find relation between them if any. It is clear that both the statements are talking about pseudo solids. Solids are basically divided in two categories, one as crystalline and other amorphous. Now in crystalline solids, the atoms are uniformly arranged throughout the solid volume whereas in amorphous solids the atoms are found to follow weak or no crystal lattice structure. This affects this second type of solids to behave differently than conventional properties of solids. Solid are substances which have a definite shape and volume. Amorphous solids too have these properties but they behave differently on exposure to forces. Where crystalline solids do not change shape when exposed to physical forces, amorphous solids change shape when exposed to forces long enough. This generally happens for example for glass. It was observed that glass panes in old monumental buildings were found to be thicker at the bottom than compared to the top of the pane. Since gravitational force continuously acts on the molecules of the glass they are forced to flow downward like a highly viscous liquid. This is thus they are also referred to as supercooled liquids. So we can say that both the given statements are correct and the second statement is the correct explanation of the first statement. Option C is the correct choice.
So, the correct answer is “Option C”.

Note: In this type of question, we need to judge the statements thoroughly and make our decision. Compare this decision with the available options carefully. Particular to this question, it is an interesting note to understand the type of solids and their distinct properties are the result of the molecular structure. Amorphous solids are observed to have a wide range of melting points. The complete volume of solid does not melt at once at one temperature because of varied molecular structure.