non-crystalline solids

Non-crystalline solids, also called amorphous solids, lack the regular, repeating atomic arrangement found in crystals. Instead, their atoms are arranged randomly, similar to liquids, but they have a fixed shape. Examples include glass and some plastics. This irregular structure means they don't have sharp melting points and may deform more easily under stress, offering unique properties such as transparency and flexibility. Despite their disordered atomic arrangement, they behave like solids because their atoms are still tightly packed and resistant to flow over short timescales.