Why does glass break?
Show answer & explanation
Answer: Stress exceeds molecular bonds
Stress exceeds molecular bonds ✓ — Correct! Glass is brittle because its molecules are locked in a rigid, amorphous structure. When force creates stress (like impact or bending), it concentrates at tiny surface flaws. Once stress exceeds the strength of molecular bonds, cracks propagate rapidly through the structure. Unlike metals that bend, glass can't deform plastically - it just breaks! That's why even small scratches weaken glass significantly.
Air pressure crushes it — Wrong. Normal air pressure doesn't crush glass. Glass breaks when applied force creates internal stress that exceeds the strength of bonds between its molecules.
Temperature melts the structure — Wrong. Glass breaks from mechanical stress, not melting. While extreme heat can soften glass, typical breaking happens when stress overcomes the molecular bonds holding the rigid structure together.
More Physics in Daily Life questions
- In a warm office that already reads 26 C, which change can make people feel cooler without lowering the thermostat?
- Why might 26 C feel acceptable in a breezy naturally ventilated summer building but too warm in a sealed winter office?
- On a warm humid day, why can the same 27 C room feel much worse once you start sweating?
- Why can moving air make a 27 C room feel cooler without changing the thermometer?
- Which hidden factor can make a desk beside a cold window feel chilly even when the thermostat across the room still reads 22 C?
- In the same 22 C room, why might someone who just climbed stairs feel warm while someone sitting in a T-shirt feels chilly?