Uranium

Uranium, with the chemical symbol U, is a chemical element and the 92nd element on the periodic table, belonging to the actinide series. It is a heavy metal with radioactivity and is mainly used in the production of nuclear energy and nuclear weapons.

Uranium is a silver-gray metal with a high density (about 19.1 g/cm³) and is solid at room temperature. It has good electrical and thermal conductivity. Uranium oxidizes rapidly in the air to form uranium oxide. It can react with many non-metals and metals to form various compounds.

Uranium has several isotopes, the most important of which are:

– Uranium-238 (U-238): accounting for about 99.3% of natural uranium. It is a non-fissile material, but can be transformed into uranium-239 through neutron capture, and is thus used in nuclear reactors and nuclear weapons.

– Uranium-235 (U-235): accounting for only about 0.7% of natural uranium. It is a fissile isotope capable of sustaining a chain reaction and is the main isotope used in nuclear power plants and nuclear weapons for fission reactions.

– Uranium-234 (U-234): a product of the decay of uranium-238, and exists in very small quantities.

The extraction of uranium is mainly achieved through mining and chemical processing of ores. Common uranium ores include pitchblende and uranophane.

Uranium is radioactive, so strict safety standards must be followed during mining, processing, and use to prevent radioactive contamination and harm to human health. In addition, the disposal and storage of uranium waste is also an important environmental issue.

Uranium was first discovered in 1789, but its radioactive properties were not discovered until the end of the 19th century. In the early 20th century, the fission properties of uranium were studied, laying the foundation for the subsequent development of nuclear energy and nuclear weapons.