Glass is a strong transparent material which has been used for centuries to make many familiar objects. Windows, bottles and drinking glasses are just a few examples. Glass is cheap to make because it is mostly made from sand.
When hot glass cools, it hardens before the molecules can arrange themselves in a regular way (like they do in metal, for example). Although glass is rigid and solid at room temperature, scientists sometimes describe glass as a liquid because of the behaviour of its molecules. Glass even acts like a liquid. Light passes through it, and when glass is heated it flows easily and can be moulded into different shapes.
Glass is transparent because of the ‘loose’ arrangement of its molecules. Ultraviolet light rays are reflected, but white and infrared light rays pass through it.
Glass is perfect for making windows because it protects you from the wind, rain and cold, but still lets the sunlight in.
Picture Credit : Google