0
It is the reverse: Np-235 decay to U-235 by electron capture.
Wiki User
∙ 6y ago
Add your answer:
Earn +20 pts
What is conserved during nuclear disintegration?
Atomic mass is conserved. Atomic number is NOT typically conserved in nuclear reactions. For example, when U235 spits out an alpha particle, its number drops by two (loss of two protons), and the mass by four, resulting in Thorium 231. The total mass is conserved, because the mass of the emitted alpha particle is 4.When an element decays by beta particle emission, the atomic number goes up by one, but the mass remains essentially the same. In spontaneous fission a pair of atoms reform with a spray of free neutrons. These neutrons have a half life of almost 15 minutes. If they bombard sufficiently heavy neighboring nuclei, what occurs is known as a fission chain reaction.
What type of nuclear decay does Uranium undergo?
Uranium has a different decay chain/series for its different isotopes. Uranium 238 for example first decays to thorium 234 through alpha decay while U235 alpha decays to thorium 231. Both have different half lifes which can be found on a natural decay series chart for the said element. The thorium in either case then beta decays to another element.
Is uranium nuclear fuel?
Yes, U233, U235, and U238 are all used as nuclear fuels.
When a unstable radioactive atom degrades what happens to it?
You probably mean decays, not degrades. When an unstable atom decays it goes through one of the following processes:Alpha decay - a helium nucleus is ejected reducing the element number by 2 and the mass number by 4.Beta decay - a neutron decays to a proton, electron, and a neutrino. The electron and neutrino are ejected increasing the element number by 1 and leaving the mass number constant.Gamma decay - the protons and neutrons in the nucleus rearrange themselves into a lower energy state and a gamma ray photon is ejected to remove the excess energy. Neither the element or mass numbers change.Fission - certain transient metastable isotopes (e.g. U236 produced by U235 capturing a neutron) can split into two smaller nuclei and eject 2 or more neutrons. Note: Fission is not usually considered a decay process.
What is meant by reactor grade materials?
This means that the nuclear material is of a high enough concentration to fissile (allow for a fission chain reaction). This is because Uranium comes naturally as 99.3% U238, which cannot sustain fission, and .7% U235, which is what they want for the fuel. So they have to find away to pull away the U238 and leave the U235. As they concentrate the U235, it becomes concentrated enough so that it can sustain fission (too much U238 bogs down the reaction and will eventually end the fission). When it reaches this point of concentration, it is concidered reactor grade. Different elements have different needed concentrations to reach this level.
What is conserved during nuclear disintegration?
Atomic mass is conserved. Atomic number is NOT typically conserved in nuclear reactions. For example, when U235 spits out an alpha particle, its number drops by two (loss of two protons), and the mass by four, resulting in Thorium 231. The total mass is conserved, because the mass of the emitted alpha particle is 4.When an element decays by beta particle emission, the atomic number goes up by one, but the mass remains essentially the same. In spontaneous fission a pair of atoms reform with a spray of free neutrons. These neutrons have a half life of almost 15 minutes. If they bombard sufficiently heavy neighboring nuclei, what occurs is known as a fission chain reaction.
What type of nuclear decay does Uranium undergo?
Uranium has a different decay chain/series for its different isotopes. Uranium 238 for example first decays to thorium 234 through alpha decay while U235 alpha decays to thorium 231. Both have different half lifes which can be found on a natural decay series chart for the said element. The thorium in either case then beta decays to another element.
Evaluation of energy output of U 235 compared to Pu 238?
I think you mean Pu-239, but we'll look at both Pu-239 and Pu-238 We'll compare to aspects, the decay energy and the fissile energy. First the decay energy. U235 alpha decays and releases 4.679 MeV in the process Pu238 alpha decays and releases 5.593 MeV Pu239 alpha decays and releases 5.245 MeV For the fissile energy. U235 fissiling releases 202.5 MeV Pu238 does not sustain a fissile, but the spontaneous fissile is 204.66 MeV Pu239 fissilings releases 207.1 MeV Pu238, because it does not sustain a fissile (though it does go through spontaneuos fissile) and because it does not emit much other stuff, other then the alpha particle, it works great as a nuclear battery. For example 8 oz of Pu238 will power the average laptop for about 29 years, without ever needing to be recharged or replaced.
Why is large mass of uranium-235 needed for a chain reaction?
Each time a U235 atom decays, it emits 2-3 neutrons. The likelihood that one of these neutrons is captured by another U235 atom INCREASES with more mass. The SHAPE of this mass will also play a role, imagine a thin wire of U235, compared to a sphere, with regards to how likely a chain reaction will occur. Neutron reflection can also help redirect an errant neutron back into the mass so it can react instead. Compression (increase of density) plays a role as well.
What is being done to reverse nuclear power?
You can't reassemble the U235 nucleus after it has fissioned, so you can't put nuclear power into reverse.
The concentration of U235 in the atomic bomb?
The references I have state Oralloy is 93.5% U235. Oralloy (Oak Ridge Alloy) was used in US Uranium atomic bombs as the fissile material. However they also say that any enrichment 20% U235 or higher is fissile and could be used to make a bomb, it would require a higher critical mass to work though. One source I have states that early Soviet Uranium atomic bombs used ~97% U235, but the US felt this level of enrichment to be unnecessary and excessively expensive.
How many neutrons are in Element 92?
Element number 92 is Uranium and there are two main isotopes - U235 and U238. In U235 there are 92 protons so there are 235 - 92 = 143 neutrons. In U238 there are thus 146 neutrons
Fission is the process of creating energy by?
On nuclear fission, small fraction of mass is loss and transform to energy. The loss mass is part of tiny sub-atomic particle. Consider reaction of Uranium U235 + n1 --> U236 --> Kr92 + Ba141+3n1 Well seem all mass is balance. But take careful step U235 is 235.0439 U236 is 236.0526 Kr92 is 91.92616 Ba141 is 140.9144 n is 1.008665 Some mass was lost and that mass go to energy as Einstein state E = mC2
What is oralloy?
Oralloy is an acronym for "Oak Ridge Alloy". Which is an alloy of Uranium 235 and Uranium 238. The U235 is the fissile isotope that is used in fission type nuclear weapons. The actual concentration is classified, but generally U235 is greater than 90%.
What is the difference between using uranium for power or bombs?
In power reactors the fuel is uranium enriched slightly to about 4 percent U235 (the fissile isotope), whereas for a bomb you need the U235 as high as possible, in the high 90's I believe.
What isotopes are in this process?
which process & which isotope u mention 1. nuclear reaction U235 & Pu239
Is uranium nuclear fuel?
Yes, U233, U235, and U238 are all used as nuclear fuels.
