Page 15 - Curriculum Visions Dynamic Book

Making glass conduct electricity
and become magnetic
Some glasses have very important electrical properties. They are known as chalcogenide glasses and contain such elements as thallium, arsenic, tellurium, and antimony. These glasses act as semi-conductors and react to light.
By coating glass, it is possible to produce an even wider range of properties. For example, a thin coating of tin oxide helps the glass reflect heat but can be thin enough that the glass stays transparent. This can also improve the energy efficiency of the glass. In winter the coating reflects heat from inside back into the room, thereby reducing heat loss. Other coatings can be used to reflect the sun’s heat in summer and keep a building cool. Such glass is found in the glass siding of many modern office blocks.
Glasses can also be made that have magnetic properties; they appear in computers and some transformers. They are metallic glasses – basically metals cooled so quickly they remain amorphous and do not develop crystal structure.
(Right) Most skyscrapers use glass with energy- efficient properties.
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