Glass is one of the most commonly used building materials in modern society and often it doesn't get a second thought. But for you, a curious mind, might wonder as to why is glass transparent in the first place and doesn't absorb light like other materials?
Well, glass is made from silicon dioxide, a common material found in sand and when heated, the molecules take on the properties of a liquid, however, when cooled it doesn't necessarily take on a solid-state again like water turning into ice, but rather the molecules retain its fluid-like characteristics but have very low amounts of energy hence its ultra-high viscosity.
The electrons that surround the nucleus are so far apart that even photons can pass through, but only at a very specific wavelength, that of visible light. However, other wavelengths of light such as ultraviolet light are absorbed by the electrons of glass particles which is the exact reason as to why you can not get a suntan through glass.
Take a look at the video below by the YouTube channel: TED-Ed on Why Is Glass Transparent? - Mark Miodownik...