Questions & Answers

State true or false.
A liquid which is permanently supercooled is frequently called glass.

Answer Verified Verified
Hint: Glass is an amorphous solid, and does not form a crystalline structure. The molecules in glass can flow. Hence it is called super cooled liquid.

Complete step by step solution:
Glass is an amorphous liquid that has been produced by super cooling. It contains a liquid solution of silica and some other selected components. It is generally defined as super cooled liquid. The main raw material used for the production of glass is silica. It is melted at a very high temperature, say $1700^o$C and cooled rapidly without allowing it to undergo recrystallization. Silica occurs as quartz in nature. Quartz is melted in a special melting furnace. Various shapes of glass are made from this molten glass. Manufacturing of glass includes three processes-pressing, blowing and drawing.
Pressing: Moulds of different shapes are filled with molten glass. It is then cooled under desired pressure.
Blowing: Air is blown in a controlled manner through the molten glass in proper containers.
Drawing: In this process, a stream of molten glass is made to pass through the molten rolls.
Different types of glasses are made by adding special compounds during the fusion. Silica glass, soda lime glass, borosilicate glass, leaded glass, pressed glass are some examples of types of glasses.

Additional information:
The molecules of glass move downward. This is the reason why the glasses are thick in nature at the bottom. Glass is more rigid than a liquid. They are transparent and easily breakable into sharp pieces.

Note: Glass has the following properties:
-High tensile strength
-Low ductility, conductivity, coefficient of thermal expansion
-High elasticity
-Resistant to acids
-High softening point