Why does window glass have no fixed melting point and can even slowly 'flow' over centuries?
Glass is amorphous — its particles are frozen in a disordered, liquid-like arrangement rather than a neat crystal lattice.
Glass is amorphous — its particles are frozen in a disordered, liquid-like arrangement rather than a neat crystal lattice. Because the bonds vary in strength, there's no single temperature at which they all break, so glass softens gradually over a range instead of melting sharply. This same lack of long-range order is why glass is often described as a supercooled liquid.
Key point
Amorphous solids lack long-range order, so they soften over a range with no sharp melting point.
Common mistake
assuming every solid has one exact melting point.
Memory tip
no ordered lattice (glass) → no sharp melting point.
Tap to watch or see it right here — the app stays open (it only opens a quick search if nothing embeddable is found).