Can nuclear fission or fusion be caused Naturally?

Question

Im doing a Science essay soon on '' The issues associated with Nuclear Energy '' I heard that stars are an example of Natural nuclear energy. But i also heard that Uranium 235 or something,,, They just split for no reason. Is that true??? And can someone explain it further for me in details???

Thank you very much

Answer 1

Nuclear Fusion (meaning nuclear Joining) occurs naturally in stars where lighter elements like hydrogen,lithium etc join to form heavier isotopes.The processes only happen at temperatures of many millions of degrees C and at pressures much greater than those at the earths centre.The new nuclei have slightly less mass than the particles that make them and this lost mass is directly turned into radiated energy as described by the well known Einstein equation E = mc^2.This is why stars like the sun shine......................................

        Nuclear fission (means nuclear splitting) occurs naturally on earth and planets because some isotopes in some elements, like thorium and uranium ,have nuclei which are too heavy to be stable .This is because they could lose mass by splitting into lighter isotopes.Again,this lost mass reappears as energy given out as radiation,this is at the heart of nuclear reactors, where it is controlled,and nuclear weapons where other considerations apply.

In response to your particular point about WHY?These reactions,like all all other other reaction happen because the processes cause the local system to lose energy.In chemistry terms carbon and oxygen burn because the CO2 produced contains less energy than the carbon and oxygen from which they came,the energy was given off as heat.The tendency for thing to happen because energy will be lost from the system is the bedrock of all systems!

Answer 2

many isotopes of many elements are unstable, meaning that they eventually decay.  Fission is the term we use for that decay; the process of an atom splitting into smaller constituents. When we use it for energy, we mass a bunch of those isotopes together so that there will be enough activity (decay) to make it worthwhile to use.  To give you an idea of how much fission actually occurs in nature, the interior heat of the earth is produced by fission, and the inside of the earth is very very hot.

The sun is dominantly fusion.  The pressures inside the sun are so great that atoms get squished together and join to make larger atoms.

Answer 3

Both occur naturally in the sun!

Answer 4

here ye be

Spontaneous fission

1st para...

Spontaneous fission (SF) is a form of radioactive decay characteristic of very heavy isotopes, and is theoretically possible for any atomic nucleus whose mass is greater than or equal to 100 u (elements near ruthenium). In practice, however, spontaneous fission is only energetically feasible for atomic masses above 230 u (elements near thorium). The elements most susceptible to spontaneous fission are the high-atomic-number actinide elements, such as mendelevium and lawrencium, and the trans-actinide elements, such as rutherfordium.

http://en.wikipedia.org/wiki/Spontaneous...

Answer 5

Yes - the Oklo reactor in Gabon, Africa was a natural fission reactor that was active about 2 billion years ago.  

As others have pointed out, stars are natural fusion reactors.

Answer 6

As people have explained, all radioactive elements decay. However, there is a case where a "natural" nuclear reactor was created by an unusual geological setting, in Gabon:

http://en.wikipedia.org/wiki/Natural_nuc...

I think that's what you were asking about, and the answer is, yes.

Answer 7

ya look at the sun....

Answer 8

Both occur naturally...

In the case of fusion, high temperatures and pressures are needed to overcome electrostatic repulsion, so it doesn't happen "naturally" on earth, but does in stars.

For fusion, all radioactive elements do it naturally.

It is because those nuclei are unstable, and they become more stable by ejecting nuclear particles (alpha radiation) or converting neutrons into protons (beta radiation).

The fact that we have learned to harness these things is down to tha fact that it does occur naturally all the time.

Answer 9

uranium 235 used for producing nuclear energy by nuclear fission. i don't know whether it occurs naturally.