[DOC] [TLE] Uranium-235 - Wikipedia [PAR] Uranium-235 (235U) is an isotope of uranium making up about 0.72% of natural 
uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can 
sustain a ... Uranium metal highly enriched in uranium-235 .... If at least one 
neutron from U-235 fission strikes another nucleus and causes it to fission, then 
the chain... [DOC] [TLE] Uranium - Periodic Table of Elements: Los Alamos National ... [PAR] Yellow glass with 1% uranium oxide was found in an ancient Roman villa near ... 
The decay series ofU, which is called the actinium series has 15 members, all of 
... is a silvery white, weakly radioactive metal, which is harder than most elements
. ... Another fissile isotope, uranium-233, can be produced from natural thorium... [DOC] [TLE] uranium-235 | chemical isotope | Britannica.com [PAR] The existence of uranium-235 in nature rests on the fact that alpha decay to the ... 
In nature, almost all (99.27 percent) of the metal consists of uranium-238; the ... 
Of these naturally occurring isotopes, only uranium-235 is directly fissionable by 
... be made to undergo fission only by fast neutrons with energy exceeding 1 MeV
. [DOC] [TLE] What is Uranium? How Does it Work - World Nuclear Association [PAR] Uranium is a very heavy metal which can be used as an abundant source of ... 
This means that it is barely radioactive, less so than many other isotopes in rocks 
and sand ... The heat created by splitting the U-235 atoms is then used to make 
steam ... can provide enough electricity for a modern city of up to one million 
people. [DOC] [TLE] Nuclear Fuel Cycle Overview - World Nuclear Association [PAR] These steps make up the 'front end' of the nuclear fuel cycle. ... Uranium is a 
slightly radioactive metal that occurs throughout the Earth's crust (see ... For most 
kinds of reactor, the concentration of the fissile uranium-235 isotope needs to .... 
uranium, of which the fissionable U-235 content has been reduced to less than 1
%. [DOC] [TLE] Facts About Uranium - Live Science [PAR] Jul 9, 2015 ... Less than a minute later, everything within a mile of the bomb's ... This radioactive 
metal is unique in that one of its isotopes, uranium-235, is the only ... It is all over 
the planet, and makes up about 2 to 4 parts per million of most rocks. ... Natural 
uranium is only about 0.7 percent U-235, the fissile isotope. [DOC] [TLE] Uranium-235 | Chemistry Learner [PAR] It is the only fissile Uranium isotope being able to sustain nuclear fission. ... 
Uranium-235 makes up around 0.72% of the total Uranium found in nature with ... 
92 protons and 143 neutrons in the nucleus of one isotope of this radioactive 
metal. ... as the chances of fission are greater with slow neutrons than with fast 
neutrons. [DOC] [TLE] Main Title Arial Bold 24pt Blue [PAR] A neutron strikes a nucleus of a heavy, unstable isotope. ... Is a dense, heavy 
metal; Consists of atoms that hold a lot of energy in their nuclei ... This causes the 
uranium in the ore to oxidize (rust) and wash out in the water. ... Only uranium-
235 is fissionable. Natural uranium in yellowcake is less than one percent U-235. [DOC] [TLE] Nuclear Chain Reaction | Bomb Grade Uranium | Natural Uranium [PAR] For a nuclear chain reaction to make a nuclear explosion we need bomb grade 
Uranium. ... bombs is highly concentrated in Uranium isotope 235 (U-235) while 
reactors use ... Less than a 20% concentration of U-235 and a nuclear explosion 
is ... The 1-3% U-235, and/or Pu-239 in reactor fuels cannot explode, regarless of
... [DOC] [TLE] Nuclear Energy - The Theory - Electropaedia [PAR] The nucleus also includes four neutrons making up its seven nucleons and thus 
a .... a radioactive silvery metal, with the emission of one Helium atom (alpha 
particle). ... The nature of the decay and the energy released depend on the 
specific ..... The content of fissile Uranium-235 used in nuclear reactors is less 
than 1% in... [DOC] [TLE] The Breeder Reactor [PAR] However,

Question: The fissionable 235 isotope makes up less than 1% of this metal in nature
Answer: uranium