why is glass considered a liquid state material?

Question

Can someone explain why glass is considered a cold liquid state? Seems just too weird. I just saw it in discovery channel but they did not explain why it is so.
thxs

I did not give you thumbs down... it must be some moron who does not know what to answer and envies you...
thxs for the explanations

Answer 1

What's a "liquid"?

Calling glass a liquid is bit of an oversimplification. While glass does have the ability to deform, stretch and flow over time, it will also fracture if overly stressed, something that is not true of classical "Newtonian" liquids like water or molasses. Glass is considered an "amorphous solid." The random, disorganized molecular structure of glass tends to slowly rearrange itself over time; this explains it's ability to "flow."

In reality, the division between liquids and solids is not very distinct. Many seemingly solid materials can behave like liquids under certain conditions. Common metals, like steel, copper, and aluminum, have a crystalline structure; but they can be made to flow like quicksand under extreme forces and pressures. The tremendous pressures in the Earth's mantle cause solid rocks to flow over millennia, and whole continents to move. A mixture of cornstarch and water is a thick liquid, but becomes momentarily solid when squeezed or compressed.

Clearly, the fact that a given material can flow, does not necessarily make it truly a liquid. In a certain sense, whether you consider glass a solid or a liquid, depends on how you define "liquid."

Hope that makes sense,
~W.O.M.B.A.T.

Answer 2

Glass is considered a liquid because the molecules are not locked in a crystal structure in the way a solid is and they can flow over one another. You can see this effect in very old panes of glass. They will be thicker at the bottom as the molecules of the glass are pulled down with the force of gravity.

Answer 3

It doesn't have a crystalline structure, which is called amorphous. It has a very high viscosity though at room temperature.