What is Soap?
[[File:Tualetsapo.jpg|thumb|right|A bar of soap]] [[File:Collage-furfur.jpg|thumb|Liquid soap]] '''Soap''' is a [[chemical compound]] resulting from the reaction of an alkali (commonly [[Sodium hydroxide|sodium]] or [[potassium hydroxide]]) with a [[fatty acid]]. Soaps are the metallic salts of long chain fatty acids. When mixed with [[water]] during [[bath]]ing, cleansing, or [[washing]], they help people and clothes get [[hygiene|clean]] by lowering the chance of [[dirt]] and [[oil]] to get to the skin or [[fabric]]. Soaps are made from [[animal]] [[fat]]s or [[vegetable oil]]s. There are two basic steps in making soap. They are called Saponification and Salting-out of soap. Some people like to make their own soap.<ref>{{Cite web|url=https://www.wikihow.com/Make-Your-Own-Soap|title=How to Make Your Own Soap|website=wikiHow|language=en|access-date=2018-12-28}}</ref> Soap cleans very well in [[soft water]]. It is not [[Toxicity|toxic]] to water life. It can be broken down by [[bacteria]]. However, it is slightly [[Solubility|soluble]] in water, so it is not often used in [[washing machine]]s. It does not work well in [[hard water]]. It cannot be used in strongly [[acid]]ic [[solution]]s. Mild hand soaps are only [[Base (chemistry)|basic]] enough to remove unwanted skin oils. For other forms of oil, dishwashing soap is strong enough to remove almost all forms of oil without damaging petroleum products such as [[plastic]]s. It does not damage skin either. Soap suds physically capture and lift [[Microorganism|germs]] (a virus, bacteria etc.) off of the surface of the skin and then water rinses them into the sink. Soap has been made in many ways. Humanity has used soap-like things for thousands of [[year]]s. The earliest recorded evidence of the making of soap-like materials dates back to around 2800 BC in Ancient [[Babylon]]<ref>{{cite book | last = Willcox | first = Michael | editor = Hilda Butler | title = Poucher's Perfumes, Cosmetics and Soaps | url = https://archive.org/details/pouchersperfumes00pouc | edit