Question

Why is glass considered a supercooled liquid?

Answer 1

Hint: To answer this question we should know that glass is an amorphous solid and liquids have the property to flow. Now try to relate these and figure out the reason for calling glass to be a supercooled liquid.

Complete step by step answer:

Let’s discuss the correct explanation for this question -

The term "glass" is defined as every solid that possesses a non-crystalline (amorphous) structure at the atomic scale and that exhibits a glass transition when heated towards the liquid state.

Glass is called supercooled liquid because glass is an amorphous solid. Amorphous solids have the tendency to flow slowly. It does not form a crystalline solid structure as particles in solids do not move but here it moves. Hence it is called a supercooled liquid.

In regular solids, there is no movement of constituent particles under normal conditions.

Glass can be considered as a liquid of extremely high viscosity. The evidence of the fact can be seen in the glass windows and doors that become slightly thicker at the bottom than at the top with the time.

Therefore, we described the reason for calling glass a supercooled liquid.

Note: You make glass by heating up liquid sand (sand mixed with silicon dioxide) and it melts into a liquid. It has to be $1700 ^oC$for it to happen though.

Sometimes crystallization of a glassy substance can happen. This is known as devitrification. A transparent piece of glass, if it is devitrified, will no longer be transparent because the many boundaries between the crystals will scatter light.