英語 English：Uranium
日語 Japanese：ウラン
元素記号 Element symbol：U (One-letter symbol)
語源 Origin：Greek Uranus (God of the sky) + Greek Ium (Metal) ⇒ English Uranium
定義 Definition：Uranium is an element with the atomic number 92. At standard temperature and pressure, uranium appears as solid metal in ore bed.
Uranium is famous as a fuel for nuclear power generation. When the uranium nucleus split, tremendous energy is generated. This phenomenon is called "nuclear fission."
Uranium is called "the most dangerous metal," and handling uranium requires a high level of technology.
類義 Synonym：Uran Atomic fuel Nuclear fuel
ウランの埋蔵量 Uranium reserves：Uranium reserves are estimated to be more abundant than precious metals such as gold, silver and platinum. Uranium deposits have been confirmed in Kazakhstan, Australia, and Canada. The reserves are dispersed in each continent.
ウランの生産 Uranium production：Uranium is produced by refining Uraninite [ $UO_2$ ] and Autunite [ $Ca(UO_2)_2(PO_4)_2·10–12H_2O$ ].
ウランとアクチニド Uranium and Actinide：Uranium is a member of the actinide series in the periodic table. The actinide series contains 15 atoms with atomic numbers 89 actinium to 103 lawrencium.
Among the actinides, atomic number 90 thorium, atomic number 91 protoactinium, and atomic number 92 uranium are naturally-occurring atoms.
Atomic number 93 neptunium and later are man-made atoms and appear through nuclear fusion.
Instead of actinides, they are sometimes called actinoids.
体系 System：化学 (Chemistry) ＞ 物質 (Substance) ＞ 分子 (Molecule) ＞ 原子 (Atom) ＞ 原子番号 (Atomic number) ＞ アクチノイド (Actinide) ＞ ウラン (Uranium)