Radium seventh of a gram of radium. One kilogram of the Earth's crust contains about 900 picograms of radium, and one liter of sea water contains about 89 femtograms of radium. Radium was discovered by Marie Sklodowska-Curie and her husband Pierre Curie on 21 December 1898, in a uraninite (pitchblende) sample. While studying the mineral earlier, the Curies removed uranium from it and found that the remaining material was still radioactive. They separated out an element similar to bismuth from pitchblende in July 1898, that turned out to be polonium. They then separated out a radioactive mixture consisting mostly of two
Radium release hitch Radium release hitch A radium release hitch is a load-releasing hitch using 3:1 mechanical advantage which is used in a two-rope technical rescue system. The Radium Release Hitch allows a load to be transferred from one rope to another and is commonly rigged into the belay line prior to the operation of a two-rope technical rescue system. A radium release hitch is typically tied with 10 meters of 8mm rope and two locking carabiners. A reasonable length for the hitch (distance between the 2 carabiners) is 10 to 15 cm. The Radium Release Hitch was developed by Kirk Mauthner (who