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Nuclear Fusion
Nuclear fusion is the phenomenon in which multiple atomic nuclei combine to form a single, larger nucleus. Fusion mostly occurs under extreme conditions, due to the large amount of energy it requires. Thus, examples of fusion tend to be exotic; such as stellar nucleosynthesis, the creation of new elements, and thermonuclear weapons.
521 Questions
What does nuclear fusion create inside of stars?
b. beryllium nuclei.
c. carbon nuclei.
d. hydrogen nuclei.
The answer is d. hydrogen nuclei.What is the purpose of nuclear fission and nuclear fusion?
Nuclear fusion is the joining together of two light nuclei to make one heavier one. It is the source of energy of the stars including our sun.
Read more: http://wiki.answers.com/What_is_nuclear_fusion_and_what_is_its_purpose#ixzz1BneLAhLF
Why does fusion occur in he sun's core but not in other layers?
Thermonuclear reactions only occur in the core of the star because that's where the heat and pressure is so great that it overcomes the forces between the atoms. The surface stars is relatively cool. The Sun is only around 10,000° F on its surface. well below the several million degrees required for fusion.
Can large nuclei undergo the process of nuclear fission?
By capture of a neutron, causing the nucleus to be unstable and to split into two parts
Where in the universe does fusion occur naturally?
Nuclear fusion is the process that powers stars, such as our sun.
What is the site of nuclear fusion on the sun?
If you are asking where does solar nuclear fusion take place, then that would be at the core of stars.
Does the nuclear fusion occurs at the surface of the sun?
Fusion takes place in the core, where the temperature and pressure are much higher, which is necessary for fusion.
Is nuclear fusion often used as an energy source in power plants?
No. Not presently. Existing power plants only use nuclear fission. Nuclear fusion is, due to technological difficulties, the greatest of which is confinement, at least 50 to 100 years away, barring some amazing discovery, of which I cannot presently conceive, given the current state of technology.
When the fusion reaction (D + T) occurs energy is released mainly in neutrons. Somehow these neutrons must be absorbed into some material which would then get hot and be able to do work. This engineering aspect has not been solved to my knowledge.
Why does fusion release energy?
Nuclear fusion releases energy, because the total mass is decreasing, as nuclear fusion is occurring. The mass of nucleus 3 is less than that of nuclei 1 and 2 combined. This '' lost" mass is converted into energy, this in accordance with Einstein's famous equation of mass-energy equivalence: E=mc2
What process takes place inside of stars?
Nuclear reactions produce the energy of the stars. Older stars undergo the triple-alpha process, while massive stars undergo the carbon cycle fusion and the Sun undergoes proton-proton fusion.Ê
WHAT IS NEEDED TO START A NUCLEAR FUSION REACTION?
It is often thought that something is needed to start the reaction, but in fact U235 naturally emits a small number of neutrons (spontaneously), so all that is needed is to achieve criticality by withdrawing control rods (in a slow careful way) and the nuclear reaction just starts.
It is critical mass that is required to initiate a chain reaction. What is critical mass? Take a breath. Critical mass is the minimum amount of fissile material that is necessary for a given geometric arrangement of that material which will cause it to begin to fission at a rate sufficient to build a chain. Because fissile material is constantly undergoing radioactive decay by spontaneous fission, at least on some small level, there will always be a few neutrons being produced by the material. If enough material is assembled in a "workable" way (speaking to the geometry), critical mass will have been achieved, and the "natural" neutron flux will initiate the nuclear chain reaction and criticality will have been achieved.There are basically a couple of applications where the implications make for a vastly different "look" to the machine that will employ the chain reaction. One is a nuclear reactor, and the other is a nuclear weapon. One will fit (approximately) in a basketball court, the other will fit in a suitcase. Let's look at them beginning with the weapon.
In a bomb, we assemble subcritical masses of fissionable material in a specific geometry, then use conventional explosives to drive those subcritical elements together. This initiates the nuclear chain reaction, and it builds very quickly and we get the big blast. The shape and arrangement of things in the bomb, its geometry, are set up so that we use as little material as possible and get a maximum yield. (Set aside variable yield weapons for now.) Enough weapons grade fissile material is used to insure critical mass is reached, and a bit more. But not to much. It's different in a nuclear reactor.
In a reactor, which is inside the pressure vessel in a pressurized water reactor, we use lots and lots of fissile material. But we spread it out over a larger volume and put a bunch of things in there to inhibit or control the nuclear chain reaction. And that means dealing with those pesky neutrons. The chain will begin when the control rods are pulled to a certain height. The rods are neutron absorbers and act to "kill" the chain when they are in the reactor core. By pulling them out, neutrons released by spontaneous natural fission within the fuel are free to cause other fissions (after a bit of slowing down) instead of being absorbed by a control rod. The chain has been initiated and builds according to the physics of the reactor.
What are some of the limitations of using nuclear fusion as a power source?
Some limitations of nuclear fusion as a power source include the challenge of containing and sustaining the high temperatures and pressures required for fusion reactions, the complexity and cost of building and maintaining fusion reactors, and the technological barriers to achieving commercially viable fusion energy production. Additionally, there are concerns about nuclear fusion producing radioactive waste and the potential for accidents or meltdowns.
What energy transformation takes place when you burn coal?
Radiant energy -> photosynthesis -> time, heat pressure = coal
coal gets burned- > heats water- > turns a turbine-> turns a generator -> produces electricity.
How are heavy elements formed during nuclear fusion?
This would be a fusion of three helium nuclei. This would happen towards the end of a star's life, it's not occurring in the sun at present, but obviously has happened in various stars in the past, which is why we have the heavy elements in our solar system
What are the processes that depend on fusion?
The energy production and nuclear reactors.
The atomic bombs used in World War II. APEX -_- ik bc I got it incorrect from the other person who answered
Is nuclear fission happening on the sun or nuclear fusion?
Fusion. Fusion requires very high temperature and pressure. So on earth we use
a critical mass of weapons grade uranium to start a fission chain reaction which
enables a fusion reaction in hydrogen. Fusion is of course more powerful than fission
Nuclear fusion occurs at the core of the sun (and other stars) providing huge amount of energy to the rest of the solar system. It has also been achieved on Earth, though not in a controlled and sustained manner.
How are nuclear fission and nuclear fusion are the same?
They are similar only in that they are nuclear reactions. In nuclear fission involves the splitting of an atomic nucleus, whereas nuclear fusion involves the joining together of atomic nuclei.
What element would more likely form during a nuclear fusion?
That depends on what element(s) are being fused.
- Fusing hydrogen produces helium
- Fusing helium produces carbon
After this the reactions get very complex, sometimes including catalytic fusion cycles of several elements. The end result of fusion is a nickel/iron alloy.
What is important about the onset of fusion?
"The onset of fusion marks the birth of stars.
Once nuclear fusion begins in a star,the prcess can continue for billions of years."
I got this info. from my text book, hope it helped you. :T
Thermonuclear fusion is a reaction in which two light atomic nuclei combine to form a heavier nucleus, releasing a large amount of energy in the process. It is the process that powers stars, like the sun, by fusing hydrogen atoms to form helium. Scientists are exploring ways to harness this process on Earth as a potential clean and sustainable energy source.
