6th-8th grade (Physical Science/Properties of Matter)
A gas hydrate is an ice-like substance that forms in deep-sea sediments when low-density gas, like methane, ethane, or carbon dioxide, combines but does not chemically bond with water and freezes into a solid under low temperature and moderate pressure conditions. In this investigation, students analyze chemical structures and make observations in order to develop and use a model to explain the phenomenon: How does methane hydrate form on and below the seafloor?
Methane Hydrate Formation Demonstration Video. Video courtesy of NOAA Ocean Exploration.
Download larger version. (mp4, 2.5 MB)