Q.What is a vitreous state ?

The vitreous state is the amorphous ('glassy') form of a solid, produced by rapid cooling that traps molecules in a disordered arrangement instead of the ordered lattice of a true crystal.

Solids are broadly classified as crystalline (particles arranged in a highly ordered, repeating three-dimensional lattice with a sharp, definite melting point and anisotropic properties) or amorphous (particles arranged with only short-range order and no long-range periodicity, melting gradually over a range of temperature, and generally isotropic). The vitreous or glassy state is the classic example of the amorphous state: when a molten material such as silica-based glass is cooled quickly, its atoms/molecules do not have sufficient time to settle into the ordered positions of a crystal lattice before viscosity becomes too high for further rearrangement, so the disordered, liquid-like structural arrangement becomes effectively 'frozen in'. Such glassy solids are therefore sometimes described as supercooled liquids of very high viscosity; being amorphou …