Question

In brittle materials such as glass, tiny imperfections at the atomic layer such as bubbled in the surface are where a crack begins to grow. Cracks spread because they stress the area around them.

True or False

Answer 1

Tiny imperfections at the atomic level can indeed initiate cracks in brittle materials like glass. Pyrex glassware is less susceptible to cracking due to its small coefficient of linear expansion, which minimizes thermal stress and makes it more resistant to thermal shock.

Step-by-step explanation:

Thermal Stress and Pyrex Glassware

It is true that in brittle materials, such as glass, tiny imperfections at the atomic level can serve as the starting point for crack growth. These imperfections, like bubbles on the surface, create stress concentrations that can initiate cracking. When it comes to materials like glass cookware, thermal stresses caused by uneven cooling can lead to breakage. Pyrex, a brand of glass with a small coefficient of linear expansion, is less susceptible to such breakage because it does not expand or contract as much as other glasses when exposed to temperature changes. This reduced expansion and contraction minimizes the development of stress within the material, making Pyrex more resistant to thermal shock and cracking.

Glass products that lack a small coefficient of linear expansion, similar to Pyrex, are more likely to crack under rapid temperature changes. When such glass is heated and then cooled unevenly or quickly, it can experience differential contraction, which results in internal stresses strong enough to cause cracking.