Uranium is a silvery-white metallic chemical element in the actinide series of the
periodic table with atomic number 92. It is assigned the chemical symbol U and naturally
found as uranium-238 , uranium-235 and uranium-234.
A uranium atom has 92 protons and 92 electrons. 6 of the latter are valence electrons. The uranium nucleus binds between 141 and 146 neutrons, establishing six isotopes, the most common of which are U-238 (146 neutrons) and U-235 (143
The major application of uranium in the military sector is in high-density penetrators.
This ammunition consists of depleted uranium (DU) alloyed with 1»2% other elements. At high impact speed, the density, hardness, and flammability of the projectile enable destruction of heavily armored targets. Tank armor and other, removable vehicle armor are also hardened with depleted uranium plates.
The discovery of the element is credited to the German chemist Martin Heinrich Klaproth
while he was working in his experimental laboratory in Berlin in 1789 and named
the newly discovered element after the planet Uranus.
Year 1841 saw the isolation of the first sample of uranium metal by heating uranium tetrachloride with potassium. Uranium was not seen as being particularly dangerous during much of the 19th century, leading to the development of various uses for the element.