uranium

/juˈreɪniəm/

/juˈreɪniəm/

Other forms: uraniums

Uranium is a dense, metallic chemical element that's used to produce nuclear power. There are tiny amounts of uranium in just about all rock, water, and soil on Earth.

Uranium's atomic number is 92, which means it has 92 protons in its nucleus. It's the heaviest element found naturally on the earth, and it's over 18 times denser than water. Uranium is also radioactive — and when scientists first managed to split a uranium nucleus in two, they realized they could use that radioactive energy to generate electricity. Eventually this power was also used to create the atom bomb. Uranium was named for the planet Uranus.

Definitions of uranium

1. noun

   a heavy, silvery-white, highly radioactive metallic element used for nuclear fuel and weapons
   synonyms: U, atomic number 92

   types:

   uranium 235

   a uranium isotope with mass number 235; capable of sustaining chain reactions

   uranium 238

   the commonest isotope of uranium; it is not fissionable but when irradiated with neutrons it produces fissionable plutonium 239

   type of:

   metal, metallic element

   any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.