> cesium is the most electropositive and sublime element known, and as such merits praise, worship, its own newsgroup (alt.cesium), etc. etc. It has a number of unique properties:
It explodes violently on contact with water or moisture in any form.
It burns with a brilliant blue flame (well metaphorically anyway). The name cesium derives from the sky-blue lines in its spectrum.
Its hydroxide (what is left after it is finished exploding with water) is the most powerful base known, and will eat through flesh, glass and many other substances.