Liquid
Liquids maintain a fixed volume, but their shape will mold to the shape of the container they are being held in.
Source
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:
"Teilchenmodell Fluessigkeit."
http://en.wikipedia.org/wiki/File:Teilchenmodell_Fluessigkeit.svg
Wikipedia
GNU FDL 1.2.
