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What is the difference between nuclear fusion and nuclear fission?It is to help me...

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hoppypolo | Student, Grade 10 | eNotes Newbie

Posted October 9, 2011 at 4:40 PM via web

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What is the difference between nuclear fusion and nuclear fission?It is to help me understand where these might occur in the universe

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ndnordic | High School Teacher | (Level 2) Associate Educator

Posted October 9, 2011 at 9:02 PM (Answer #1)

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Nuclear fission is a natural process that occurs with many elements. One or more isotopes of many elements are unstable and they will naturally break apart into smaller pieces.  When they break up this process is called nuclear fission. Nuclear because the nucleus of the atom is involved and fission or splitting because the nucleus breaks up into smaller pieces. When fission occurs a small amount of energy is also released as each atom splits. You cannot stop fission from taking place but the rate can be increased.  Two examples of fission reactions are nuclear power generation and atom bombs. In nuclear power generation Uranium-235 splits and energy is released. By allowing large numbers of Uranium atoms to split in a controlled manner much energy is released which is used to heat water and turn it into steam. The steam then turns generators to produce electricity.

In an atom bomb large numbers of Uranium atoms split rapidly in an uncontrolled manner and a tremendous amount of energy is released very rapidly.

Nuclear fusion is also a natural process in which the nuclei of small elements are forced together to make larger elements. This process requires very high temperatures and pressures to force the nuclei together. The fusion process is what is believed to fuel the energy release that takes place in the sun and other stars.  The only current example of nuclear fusion on earth is when a hydrogen bomb is exploded.

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m-a-padmanabha-rao | College Teacher | eNotes Newbie

Posted November 27, 2011 at 12:42 AM (Answer #2)

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Solar XUV is identified as Bharat Radiation emission from radioisotopes produced by uranium fission

http://www.angelfire.com/sc3/1010/XUV-Linked-to-Bharat-Radiation.html

Uranium fission seems to take simultaneously at several places on the core of the Sun. The site of fission appears as Sun spot to a distance through satellites. During solar maximum number of these sun spots would be more and the number gradually falls during waning period until no spots are seen at solar minimum during 11 year solar cycle. Notably, the UV, VIS, and NIR radiations also result from fission fragments (radioisotopes) reaching the Earth, by Padmanabha Rao Effect. The raise in NIR radiation caused by hard γ and β emissions from long lived fission products such as 90Sr + 90Y may have to be taken into consideration in regards to warming the Earth's atmosphere. Besides the current wisdom that fusion powers Sun light, this alternative approach helps to examine whether Padmanabha Rao Effect really causes UV dominant Sun light from radioisotopes, produced by Uranium fission.

  • Measurements of certain wavelengths in solar spectrum reported since 1960s where gap is supposed to exist are now identified as Bharat wavelengths caused by γ, β or XRF energy, confirming solar Bharat wavelengths and EUV originate from radioisotopes produced by Uranium fission.
  • Solar tritium supports the view on uranium fission in Sun.
  • Solar neutrons support the view on Uranium fission taking place in Sun

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