What is uranium?

Uranium is a grey metallic chemical element of the actinide series, its chemical symbol is "U" and its atomic number is 92. It has the highest atomic weight of all naturally occurring elements and is approximately 70% denser than lead.

It is slightly radioactive and occurs naturally in the earth's crust in a mixture of three isotopes: 0.02% U-234 (considered trace level), 0.7% U-235, and 99.28% U-238.

Three interesting facts:

• It is rarely used in its pure state and is usually worked with its oxides.
• It is 500 times more abundant than gold
• The only known use is as fuel for nuclear reactors.

It was discovered in 1789 by the German physicist M. H. Klaproth. Why did he call it that? In honour of the planet Uranus, located eight years earlier.

To find out how uranium is used as a nuclear fuel click here.