Page 24 - Curriculum Visions Dynamic Book

Uranium
The element uranium, chemical symbol U, is named for the planet Uranus, since the planet was discovered in 1781, just eight years before the element uranium.
Uranium, a silvery-white, extremely dense metal, was first discovered in the mineral pitchblende. Uranium is not an especially
rare mineral. It is more plentiful than, say, mercury or silver. However, it has become
of vital importance in the nuclear age. An overwhelmingly large proportion
of uranium on Earth is uranium-238.
This makes it the heaviest atom commonly found in nature. Uranium turns blue in
air because it develops an oxide coating.
Uranium is not found in concentrated
form; many tonnes of ore have to be processed to obtain even one gram of the element.
The biggest deposits of uranium ore are at Blind River, Canada, in South Africa, Australia, France, and in Colorado and Utah in the United States.
The most important compound of uranium is uranium hexafluoride gas, which can be used to separate uranium-238 from uranium-235, the main ingredient of the atomic bomb.
Release of energy
Uranium can be used to release enormous amounts of energy, for both peaceful and military purposes. The energy released by a kilogram of uranium
is about two and a half million times the energy released by burning one kilogram of coal.
The main way the energy is released is known as nuclear fission. It is described on page 28.
 A uranium mine in Namibia. Notice how the mine is geared to extracting very large quantities of rock. The structures on the site include concentrating plants to improve the proportion of element to rock as much as possible before transporting it to a smelter.
 A sample of uranium ore or pitchblende.
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