Glass is what kind of solid

Old windows are uneven. Some once thought this was because glass is a liquid that flows down slowly over the centuries. Solving the challenge, determining whether glass can become truly solid, requires identifying a clear transformation, the equivalent of liquid water freezing to ice as temperature changes. Of course glass can be found in a liquid state, but does it become a true solid once it cools down? On cooling we cannot definitively say yet that glass has become a solid.

Glass is so poorly understood that if a transition occurs it is far from universally accepted. During a scientific revolution, many interpretations of what is happening compete before one interpretation becomes accepted by the scientific community as being correct.

Molecules in a viscous liquid. Blue regions are solid-like, green, yellow and red atoms are more liquid-like. With a "solid—if you grab it, it holds its shape," he adds. When glass is made, the material often containing silica is quickly cooled from its liquid state but does not solidify when its temperature drops below its melting point. At this stage, the material is a supercooled liquid, an intermediate state between liquid and glass. To become an amorphous solid, the material is cooled further, below the glass-transition temperature.

Past this point, the molecular movement of the material's atoms has slowed to nearly a stop and the material is now a glass. This new structure is not as organized as a crystal, because it did not freeze, but it is more organized than a liquid. For practical purposes, such as holding a drink, glass is like a solid, Ediger says, although a disorganized one. Like liquids, these disorganized solids can flow, albeit very slowly.

Over long periods of time, the molecules making up the glass shift themselves to settle into a more stable, crystallike formation, explains Ediger.

The closer the glass is to its glass-transition temperature, the more it shifts; the further away from that changeover point, the slower its molecules move and the more solid it seems. Whatever flow glass manages, however, does not explain why some antique windows are thicker at the bottom.

Helmenstine holds a Ph. She has taught science courses at the high school, college, and graduate levels. Facebook Facebook Twitter Twitter. Updated February 02, Glass is a solid. It has a definite shape and volume. It does not flow. Specifically, it is an amorphous solid because the silicon dioxide molecules are not packed in a crystal lattice. The reason people thought glass might be a liquid was because old glass windows were thicker at the bottom than at the top. The glass was thicker some places than others because of the way it was made.

It was installed with the thicker part at the bottom because it was more stable. If you want to get technical, glass can be a liquid when it is heated until it is melted.

However, at room temperature and pressure, it cools into a solid. Featured Video. Cite this Article Format.

Helmenstine, Anne Marie, Ph. Is Glass a Liquid or a Solid? The Composition and Properties of Glass. Liquid Elements on the Periodic Table. Silicon Facts Atomic Number 14 or Si. Only time will tell how we can use this new glass. And just think, this all started because of an accidental discovery!

If you see rippling in old windows, it is the result of old manufacturing practices, not the result of flow. Glass — Chemistry Encyclopedia — structure, reaction, water, uses, elements, metal, property.

Chemistry of Glass. He received his Ph. View all posts. Need it in your inbox to read with your morning coffee? Sign up and receive our email digest with our latest blogs once a month! Click here to sign up. Illinois Science Council Science for the Curious.

Skip to content Glass is a solid, right? But wait! Come to think of it, how do we define solids, liquids, and gasses at the molecular level?

Properties of solids, liquids, and gasses. From the Fuse School.