How does a solid like glass differ from ice in terms of melting behavior?

How does a solid like glass differ from ice in terms of melting behavior?

• A. Ice has a sharp melting point; glass is an amorphous solid that softens gradually over a range of temperatures.
• B. Ice has a sharp melting point and melts suddenly, while glass never melts.
• C. Glass melts at the same fixed temperature as ice.
• D. Both ice and glass melt gradually but never fully melt.

Answer: (B)

Melting behavior depends on structure. Ice is a crystalline solid, so it has a specific melting temperature at which it changes abruptly from solid to liquid. Glass is an amorphous solid, lacking long-range order, so there isn’t a single temperature where it suddenly becomes a liquid; it gradually softens over a range of temperatures and can flow slowly as it gets hotter. This contrast—ice melting sharply at a point versus glass softening over a range—is why that description best captures the difference. (Note: glass can melt at very high temperatures, but it does not have a single sharp melting point like ice.)

Melting behavior depends on structure. Ice is a crystalline solid, so it has a specific melting temperature at which it changes abruptly from solid to liquid. Glass is an amorphous solid, lacking long-range order, so there isn’t a single temperature where it suddenly becomes a liquid; it gradually softens over a range of temperatures and can flow slowly as it gets hotter. This contrast—ice melting sharply at a point versus glass softening over a range—is why that description best captures the difference. (Note: glass can melt at very high temperatures, but it does not have a single sharp melting point like ice.)