Glass Expansion and Contraction Experiment: Will It Shatter?

Glass Expansion and Contraction Experiment: Will It Shatter?

Glass, as a solid material, is often perceived as fragile, but its response to temperature changes depends greatly on its composition and structure. The classic thermal expansion and contraction experiment aims to test just how much glass can endure when subjected to sudden heating or cooling.

Ordinary soda-lime glass, commonly found in windows and bottles, has a relatively high coefficient of thermal expansion. This means that when it is exposed to rapid temperature changes—for example, being heated with a flame and then quenched in cold water—it experiences internal stress. Since glass is brittle and lacks the ability to deform plastically, these stresses can quickly lead to cracking or even explosive shattering.

On the other hand, borosilicate glass—widely used in laboratories, cookware, and industrial equipment—shows very different behavior. Thanks to its lower thermal expansion coefficient (about 3.3 × 10⁻⁶ /K, compared to soda-lime glass’s 9 × 10⁻⁶ /K), borosilicate can withstand drastic temperature swings without fracturing. That’s why beakers, test tubes, and heat-resistant kitchenware are able to move from hot to cold conditions far more safely.

The experiment typically involves heating a glass sample with a flame, then rapidly immersing it in ice water. With ordinary glass, the result is usually cracking or a sharp shatter. With borosilicate, however, the piece often remains intact, demonstrating its superior thermal stability.

So, will the glass shatter? The answer depends on the type of glass. Ordinary glass is very likely to break under sudden thermal shock, while borosilicate glass can resist it impressively. This experiment not only illustrates material science in action but also highlights why glass selection is critical in scientific, industrial, and even household applications.