just a general interest thing for chemists. i was shown this youtube video the other day: http://youtube.com/watch?v=gRuoWkOlaHM it is the show Brainiac and they are demonstrating Alkaline Metals reacting with water. They show brief Lithium, Sodium and Potassium reactions; then drop 2g of Rubdium and Caesium into different bathtubs. and wow. :) must see!