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Uranium-235

Uranium-235 is an isotope of uranium Uranium

Uranium is a chemical element [i] in the periodic table [i] that has the symbol U and atomic number [i] ... 

 that differs from the element's other common isotope, uranium-238 Uranium-238

Uranium-238, is the most common isotope [i] of uranium [i] found. ... 

, by its ability to cause a rapidly expanding fission Nuclear fission

For the generation of electrical power by fission, see Nuclear power plant [i] ... 

 chain reaction, i.e., it is fissile. In fact, U-235 is the only fissile isotope found in any quantity in nature. It was discovered in 1935 by Arthur Jeffrey Dempster. If at least one neutron Neutron

In physics [i], the neutron is a subatomic particle [i] with no net electric charge [i] and a mass [i] o ... 

 from U-235 fission strikes another nucleus and causes it to fission, then the chain reaction will continue. If the reaction will sustain itself, it is said to be critical, and the mass of U-235 required to produce the critical condition is said to be a critical mass Critical Mass

Critical Mass is a bike ride typically held on the last Friday of every month in cities [i] around ... 

.

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Encyclopedia

Uranium-235
General
Name, symbol Uranium-235, 235U
Neutron Neutron

In physics [i], the neutron is a subatomic particle [i] with no net electric charge [i] and a mass [i] o ... 

s
143
Proton Proton

In physics [i], the proton is a subatomic particle [i] with an electric charge [i] of one positive fundamental unit [i] ... 

s
92
Nuclide Data
Natural abundance 0.72%
Half-life 7.038·108 years
Decay products Thorium-231
Isotope mass 235.0439299 u
Spin 7/2-
Excess energy 40914.062 ± 1.970 keV
Binding energy Binding energy

Binding energy is the energy [i] required to disassemble a whole into separate parts. ... 

1783870.285 ± 1.996 keV
Decay mode Radioactive decay

Radioactive decay is the set of various processes by which unstable atomic nuclei [i] ... 

Decay energy
SF n/a MeV
Alpha decay 4.679 MeV
  
  

Uranium-235 is an isotope of uranium Uranium

Uranium is a chemical element [i] in the periodic table [i] that has the symbol U and atomic number [i] ... 

 that differs from the element's other common isotope, uranium-238 Uranium-238

Uranium-238, is the most common isotope [i] of uranium [i] found. ... 

, by its ability to cause a rapidly expanding fission Nuclear fission

For the generation of electrical power by fission, see Nuclear power plant [i]
... 

 chain reaction, i.e., it is fissile. In fact, U-235 is the only fissile isotope found in any quantity in nature. It was discovered in 1935 by Arthur Jeffrey Dempster.

If at least one neutron Neutron

In physics [i], the neutron is a subatomic particle [i] with no net electric charge [i] and a mass [i] o ... 

 from U-235 fission strikes another nucleus and causes it to fission, then the chain reaction will continue. If the reaction will sustain itself, it is said to be critical, and the mass of U-235 required to produce the critical condition is said to be a critical mass Critical Mass

Critical Mass is a bike ride typically held on the last Friday of every month in cities [i] around ... 

. A critical chain reaction can be achieved at low concentrations of U-235 if the neutrons from fission are moderated to lower their speed, since the probability for fission with slow neutrons Neutron temperature

The neutron temperature, also called the neutron energy, indicates a free neutron's [i] ... 

 is greater. A fission chain reaction produces intermediate mass fragments Fission product

Fission products are the residues of fission [i] processes. ... 

 which are highly radioactive Radioactive decay

Radioactive decay is the set of various processes by which unstable atomic nuclei [i] ... 

 and produce further energy by their radioactive decay Radioactive decay

Radioactive decay is the set of various processes by which unstable atomic nuclei [i] ... 

. Some of them produce neutrons, called delayed neutrons, which contribute to the fission chain reaction. In nuclear reactor Nuclear reactor

A nuclear reactor is a device in which nuclear chain reaction [i]s are initiated, controlled, and sustai ... 

s, the reaction is slowed down by the addition of control rods Control rod

A control rod is a rod made of chemical element [i]s capable of absorbing many neutrons [i] without fiss ... 

 which are made of element Chemical element

A chemical element, often called simply an element, is a substance [i] that can... 

s such as boron Boron

|-
| colspan="6" align="center" | *Boron-10 content may be as low as 19.1% and ashigh as 20.3% in natural samp... 

, cadmium Cadmium

Cadmium is a chemical element [i] in the periodic table [i] that has the symbol Cd and atomic number [i] ... 

, and hafnium Hafnium

Hafnium is a chemical element [i] in the periodic table [i] that has the symbol Hf and atomic number [i] ... 

 which can absorb a large number of neutrons. In nuclear bomb Nuclear weapon

A nuclear weapon derives its destructive force from nuclear reaction [i]s of fission [i] ... 

s, the reaction is uncontrolled and the large amount of energy Energy

In general, the concept [i] of energy refers to "the potential for causing changes." The word is used in ... 

 released creates a nuclear explosion Effects of nuclear explosions

A nuclear explosion occurs as a result of the rapid release of energy from an uncontrolled nuclear reaction [i] ... 

.



The fission of one atom of U-235 generates 200 MeV = J, i.e. 18 TJ/mol = 77 TJ/kg.

Only around 0.72% of all natural uranium is uranium-235, the rest being mostly uranium-238 Uranium-238

Uranium-238, is the most common isotope [i] of uranium [i] found. ... 

. This concentration is insufficient for a self sustaining reaction in a light water reactor; enrichment Enriched uranium

Enriched uranium is uranium [i] whose uranium-235 [i] content has been increased through the process of ... 

, which just means separating out the uranium-238, must take place to get a usable concentration of uranium-235. Pressurised Heavy Water Reactors, other heavy water reactors, and some graphite moderated reactors are known for using unenriched uranium. Uranium which has been processed to boost its uranium-235 proportion is known as enriched uranium Enriched uranium

Enriched uranium is uranium [i] whose uranium-235 [i] content has been increased through the process of ... 

, different applications require unique levels of enrichment.

The fissile uranium in nuclear weapon Nuclear weapon

A nuclear weapon derives its destructive force from nuclear reaction [i]s of fission [i] ... 

s usually contains 85% or more of 235U known as weapon-grade, though for a crude, inefficient weapon 20% is sufficient ; even less is sufficient, but then the critical mass Critical Mass

Critical Mass is a bike ride typically held on the last Friday of every month in cities [i] around ... 

 required rapidly increases. However, judicious use of implosion and neutron reflector Nuclear weapon design

Nuclear weapon designs are physical, chemical, and engineering arrangements which allow for the detonati... 

s can enable construction of a weapon from a quantity of uranium below the usual critical mass for its level of enrichment, though this would likely only be possible in a country which already had extensive experience in developing nuclear weapons. The Little Boy Little Boy

Little Boy was the codename [i] of the atomic bomb [i] which was dropped on Hiroshima [i] ... 

 atomic bomb was fueled by enriched uranium. Most modern nuclear arsenals use plutonium Plutonium

Plutonium is a radioactive [i], metal [i]lic chemical element [i].... 

 as the fissile component, however U-235 devices remain a nuclear proliferation Nuclear proliferation

Nuclear proliferation is the spread of nuclear weapons [i] production technology and knowledge to nation ... 

 concern due to the simplicity of the design Nuclear weapon design

Nuclear weapon designs are physical, chemical, and engineering arrangements which allow for the detonati... 

.

Uranium-235 has a half-life of 700 million years.

See also

  • Uranium Market Uranium market

    The uranium market, like all commodity markets, has a history of volatility, moving not only with the st... 

  • Nuclear reprocessing
  • United States Enrichment Corporation
  • Nuclear fuel cycle Nuclear fuel cycle

    The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel [i] thr ... 

  • Nuclear power Nuclear power

    Nuclear power is the controlled use of nuclear reactions [i] to release energy for work including propulsion [i] ... 



References



External links