SCIENCE
'( <a href="http://www.j-archive.com/media/2007-07-12_J_18.jpg" target="_blank">Kelly delivers the clue from the lab.</a> ) Normally, an ice cube floats; <a href="http://www.j-archive.com/media/2007-07-12_J_18a.jpg" target="_blank">this one, however, sinks right to the bottom</a> because it's made of heavy water, or D<sub>2</sub>O; the D standing for this isotope'
deuterium