What is Silk?
[[File:Court ladies pounding silk from a painting (捣练图) by Emperor Huizong.jpg|thumb|Court ladies pounding silk]] [[File:Meyers b14 s0826a.jpg|thumb|Four of the most important domesticated silk worms, together with their adult moth forms, [[Meyers Konversations-Lexikon]] (1885-1892)]] '''Silk''' is a natural [[fibre]] made by the [[silk worm]] cocoon. Silk fibres are very strong and are often used to make [[cloth]]. The cloth from silk can be made into [[rug]]s, [[bed]]ding, or can be used to [[writing|write]] or [[painting|paint]] on. In the past, silk was used to make [[parachute]]s. The practice of growing silkworms for silk production is called ''sericulture''. Most [[spider]]s make a natural fibre of their own that is also called silk. == History == The practice of breeding silkworms, known as [[sericulture]], dates back to around 5000 BC during the time of the Yellow Emperor, Huang Di. Legend says that his wife, [[Leizu|Lei Zu]], introduced silkworm rearing and invented the loom, earning her the title [[Goddess of Silk.]]<ref>{{Cite web|title=History of Silk {{!}} China Collection|url=https://china.lu/en/silk-30|access-date=2024-10-02|website=china.lu}}</ref> ==Chemical properties== Silk that is made by the silk worm is made up of two main [[protein]]s, [[sericin]] and [[fibroin]]. Fibroin is the structural center of the silk and gives it its [[Strength of materials|strength]]. It is made up of [[amino acid]]s, which make the [[fiber]]s strong and hard to break. The [[tensile strength]] is there because of [[hydrogen bond]]s. When silk is stretched, there is a strong [[Force (physics)|force]] on these many bonds, so they do not break. Serecin is the sticky material which surrounds the fibroin and gives it protection from the outside. Silk is resistant to most [[mineral acid]]s, except for [[sulfuric acid]], which dissolves it. [[Perspiration]] gives the silk a [[yellow]]ish colour. ==Related pages== * [[Silk Road]] ==References== {{commonscat|Silk}} {{reflist}} [[Category:Basic English 850 words