Gas
Does not have a defininite shape
Atoms and molecules are spread out and move rapidly
Gases hold huge amounts of energy
http://www.bbc.co.uk/schools/scienceclips/ages/9_10/gases_fs.shtml
http://www.chem4kids.com/files/matter_gas.html
http://www.sciencekids.co.nz/gamesactivities/gases.html