What is Nuclear fission: Definition and 88 Discussions
Nuclear fission is a reaction in which the nucleus of an atom splits into two or more smaller nuclei. The fission process often produces gamma photons, and releases a very large amount of energy even by the energetic standards of radioactive decay.
Nuclear fission of heavy elements was discovered on December 17, 1938 by German Otto Hahn and his assistant Fritz Strassmann at the suggestion of Austrian-Swedish physicist Lise Meitner who explained it theoretically in January 1939 along with her nephew Otto Robert Frisch. Frisch named the process by analogy with biological fission of living cells. For heavy nuclides, it is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation and as kinetic energy of the fragments (heating the bulk material where fission takes place). Like nuclear fusion, in order for fission to produce energy, the total binding energy of the resulting elements must be greater than that of the starting element.
Fission is a form of nuclear transmutation because the resulting fragments (or daughter atoms) are not the same element as the original parent atom. The two (or more) nuclei produced are most often of comparable but slightly different sizes, typically with a mass ratio of products of about 3 to 2, for common fissile isotopes. Most fissions are binary fissions (producing two charged fragments), but occasionally (2 to 4 times per 1000 events), three positively charged fragments are produced, in a ternary fission. The smallest of these fragments in ternary processes ranges in size from a proton to an argon nucleus.
Apart from fission induced by a neutron, harnessed and exploited by humans, a natural form of spontaneous radioactive decay (not requiring a neutron) is also referred to as fission, and occurs especially in very high-mass-number isotopes. Spontaneous fission was discovered in 1940 by Flyorov, Petrzhak, and Kurchatov in Moscow, in an experiment intended to confirm that, without bombardment by neutrons, the fission rate of uranium was negligible, as predicted by Niels Bohr; it was not negligible.The unpredictable composition of the products (which vary in a broad probabilistic and somewhat chaotic manner) distinguishes fission from purely quantum tunneling processes such as proton emission, alpha decay, and cluster decay, which give the same products each time. Nuclear fission produces energy for nuclear power and drives the explosion of nuclear weapons. Both uses are possible because certain substances called nuclear fuels undergo fission when struck by fission neutrons, and in turn emit neutrons when they break apart. This makes a self-sustaining nuclear chain reaction possible, releasing energy at a controlled rate in a nuclear reactor or at a very rapid, uncontrolled rate in a nuclear weapon.
The amount of free energy contained in nuclear fuel is millions of times the amount of free energy contained in a similar mass of chemical fuel such as gasoline, making nuclear fission a very dense source of energy. The products of nuclear fission, however, are on average far more radioactive than the heavy elements which are normally fissioned as fuel, and remain so for significant amounts of time, giving rise to a nuclear waste problem. Concerns over nuclear waste accumulation and the destructive potential of nuclear weapons are a counterbalance to the peaceful desire to use fission as an energy source.
Homework Statement
What is the amount of energy released when 1g of uranium 235 undergoes fission? Fission of uranium is: uranium + n -> Ba + Kr +12n.
Homework Equations
E=Δmc^2
The Attempt at a Solution
I found the mass of the reactants to be 236.05256u and the products to be...
Hello,
I am doing a small research investigation into whether Nuclear Fusion will provide a safer and as efficient energy source as current Fission technology. Just interested if anybody has opinions on the topic and what their stance is on Nuclear Fusion, do they think it can work, any...
Hello, I have been really interested in nuclear fission in my life, however, have not studied anything solid in the field. I have, however, read a little about it.
Basically, I know that in order for fission to take place, a neurton needs to collide with a large, dense nucleus. What I do not...
Is there any possible way to extract energy that isn't in terms of heat in a nuclear reaction? It seems like a very passive way to collect energy. There are many medium transports from the reactor to the actual steam turbine (e.g. supercritical water, molten sodium, etc). Is there any proposed...
The binding energy per nucleon of each nucleus is as follows.
235
U : 1.2191 x 10^-12 J
92144
Ba : 1.3341 x 10^-12 J
5690
Kr : 1.3864 x 10^-12 J
36Use the data to calculate
1/ The energy release in this fission reaction( give your answer to 3 significant figures)The answer to the...
Homework Statement
For my essay on nuclear fission and fusion, I have to discuss some experimental evidence for nuclear fusion. I also need to find info about scientist that are responsible for developing the theory behind nuclear fusion. I am having trouble find info on these aspect.
Any...
Homework Statement
Example nuclear fission:
{}_{92}^{235}U+{}_{0}^{1}n \rightarrow {}_{38}^{90}Sr+{}_{54}^{163}Xe+10{}_{0}^{1}n+Q
How much energy does such fission release?
Homework Equations
I'm given the values of M({}^{235}U), m_{n}, M({}^{90}Sr), M({}^{136}Xe) but I've not...
Looking at the fission of Uranium 235, the typical end product will be Barium 141 and Krypton 92, and 3 neutrons.
From this, we can calculate the energy that the fission gives off, by taking the difference in mass of the product and "reactant", and use the equation of E=mc2.
But what i see...
1. What is the energy released in the fission reaction 10n + 23592U --> 14156Ba + 9236Kr + 310n?
2. I am pretty sure this has to do with binding energies, but other than that I'm completely lost.
Please help. Thank you so much.
Is it possible to use fisssion to create plasmas, then use the plasma to generate electricity instead of suing steam to for elctricity? Just a thought.
Homework Statement
Another possible form of the fission of U-235 is:
\begin{array}{cc}235&92\[\tex] U + \begin{array}{cc}1&0\[\tex] n [tex]/rightarrow [tex]\begin{array}{cc}141&56\[\tex] Ba + [tex]\begin{array}{cc}92&36\[\tex] Kr + 3 [tex]\begin{array}{cc}1&0\ n
a) Given the masses of the...
Energy Principle and Nuclear Fission Rhenium HELP! ASAP
Homework Statement
For some isotopes of some very heavy nuclei, including nuclei of thorium, uranium, and plutonium, the nucleus will fission (split apart) when it absorbs a slow-moving neutron. Thorium-227, with 90 protons and 137...
I'm looking for the most common thermal fission products for U-233, U-235, Pu-239 and Pu-241. As far as I understand it there are two quantities of interest, the cumulative fission yield and the independent fission yield. The latter being "number of atoms of a specific nuclide produced...
Homework Statement
How many kilograms of U-235 would be needed to run a 707 MW reactor for 1 year?
Homework Equations
183.9 MeV released per reaction
7.57E26 reactions per year
(These numbers are from the prior problems)
The Attempt at a Solution
I thought maybe half life, but...
If anyone can help me with this question I'd be greatly appreciative...
Here's what I think I understand:
Nuclear fission is the breaking of an atomic core of an atom. Like with U-235.
It absorbs a slow moving neutron which yields the unstable U-236. Because of the instability the atomic...
The nuclear fission does not work!
No infraction please!
I was perhaps mistakenly under the impression that matter was destroyed in nuclear
fission, but a careful look at this diagram (top right) appears to show all the
protons, neutrons and electrons are balanced in the equation...
1. Homework Statement [/b]
The overall question is:
For this assignment explain how the E=mc2 equation applies to nuclear fission. In your answer illustrate your explanation with an example, being sure to distinguish between mass and mass number, and explain how a nuclear equation differs...
I am trying to come up with an example to illustrate how E=mc2 applies to nuclear fission. I need to be sure to distinguish between mass and mass number. I feel like I have some thing on the brink of my mind and then I loose it. I guess I need some help as I am tired and don’t know how much...
What nuclear fission reactor design has the least environmental impact? Including the building, operating, safety, and amount of pollution produced?
I'd imagine IFR/breeder reactors as they burn actinides.
hi guys, iam kinda stuck on 2 problems. here is what it is :
The nuclear fission reaction of uranium-235 with one neutron produces germanium-81, 5 neutrons and another element, what element is that? what's the atomic number andatmoic mass,?give the equation.
2. how much energy is...
uranium is f-block element..is there any relation between f-block elements and nuclear fuel...what i mean is ,i think f-block elements have more probablity of becoming nuclear fuel..is this correct?..
i have some basic doubts...why is that nuclear fission is done only on heavy nucleus..what stops to perform nuclear fission on lighter nucleus..what are the lighter nucleus that are used for fission if any?
[SOLVED] Nuclear fission and amount of U-235 used
Homework Statement
At the fission of a U-235 atom about 200 MeV of energy is released. How many fissions occur in 1 second in an power plant which has the heat energy capacity of 2050 MW? How much U-235 is consumed in one year (330 days)...
Homework Statement
If Bill put enough radioactive matter in one place, the chain reaction associated with multiple radioactive decays can be made to run out of control and will form an atomic bomb. What do we call this amount of matter?
Homework Equations
The Attempt at a Solution
Homework Statement
Find the energy released of the follow fission reaction:
\displaystyle{^{1}_0}n\; +\; ^{235}_{92}U\; \rightarrow \; ^{88}_{38}Sr\; +\; ^{136}_{54}Xe \;+\; 12 ^{1}_{0}n}
Homework Equations
E=mc^2
The Attempt at a Solution
How come the masses between the...
in nuclear fusion, 2 nuclei join to make one correct,
therefore there is a loss of mass and energy, that energy escapes as gamma rays etc.
but in nuclear fission, as the binding energy increases surely energy must have to come from somewhere, but apparently energy is given out?
also my...
Hi, I am studying in 10th Standard and preparing for final exams,
anyone please help for this following question.
When Uranium undergoes Nuclear Fission, 0.1 %(percentage) of total mass is converted into energy. Calculate tota amount of energy in Joules during an explosion of atom bomb...
I can't quite understand critical mass. They say in a fission bomb they have to separate two blocks of fissile Uranium of subcritical mass so they won't undergo spontaneous fission.
What exactly is critical mass? Is it just the amount of Uranium held in one place at one time and if so why...
Homework Statement
1. Which of the following statements is / are not correct?
(1) In fission, two large fragments of equal masses are produced from a nuclide.
(2) Natually occurring elements perform fission spontaneously.
(3) 2 H2O --> 2H2 + O2 involves nuclear fission.
Homework...
hey need to write a paper on the advantages and disadvantages of nuclear fission.. this is briefly what i have come up with:
Advantages:
1) Nuclear Power: efficient and a good alternative to coal which is exhaustible..
Disadvantages:
1) It resulted in the development of atomic...
This is probably an easy question for most of you, but me nor my teacher knew. Today we learned that nuclear fission can occur when a neutron "hits" the nucleus of Uranium-235. What i wanted to know is, where does this neutron come from, and how can they make it hit this uranium-235 atom.
Any...
"nuclear" fission produces quark mass
A top quark is roughly 32 times more massive than a bottom quark.
A charm quark is roughly 8 times more massive than a strange quark.
And a down quark is roughly 2 times more massive than an up quark.
In nuclear fission 2 neutrons yield 4 neutrons...
Hi, just unsure about a question I wonder if you can help me with: How do the neutrons released after nuclear fission differ from those absorbed to begin the reaction in the first place. I think this may be asking me about delayed neutrons, but this is more to do with how the neutrons are made...