Question

When you pour hot tea suddenly on to a glass tumbler, it cracks. Because:
A.Glass cannot resist heat
B.Glass expands unevenly around the place of contact with the tea
C.Tea has chemicals which react with glass tumblers
D.The reason is yet to be discovered by scientists

Answer 1

Some materials do not allow the heat to pass through them and are known as bad heat conductors or heat insulators, weak heat conductors are the insulators, good insulators are the bad conductors, and they are materials through which the heat does not move. Glass is an insulator. As seen in substances such as copper and other metals that are excellent conductors of both heat and electricity, this does not allow electrons to flow easily from atom to atom. Insulators have electrons that are kept closely, which suggests that other atoms do not exchange them.

Complete answer:
One side of the glass expands as the hot tea is poured into the glass tumbler, while the other side doesn't. As glass is not a strong heat conductor, it splits.
Hence, Option (B) is the correct answer.

Additional information:
The metals are better conductors because they contain free electrons, the electrons move through the metal easily, They gain the kinetic energy from collisions with hot atoms and pass on the energy when they collide with cold atoms, This transfers the heat more quickly.

Note:
If a material is a strong heat conductor, the heat will transfer easily. Metals are commonly used for the purpose of heat transfer because they have properties that allow heat to disperse (movement in a line) while being able to withstand the extremes of temperature that are often associated with heating.