what is difference between nuclear fission & nuclear fusion ? give the answer pointwise in a tabular form ?

Nuclear fusion is the reaction in which two or more nuclei combine together to form a new element with higher atomic number (more protons in the nucleus).

The energy released in fusion is related to E = mc 2 (Einstein’s famous energy-mass equation). On earth, the most likely fusion reaction is Deuterium-Tritium reaction. Deuterium and Tritium are both isotopes of hydrogen.

2 1 Deuterium + 3 1 Tritium = 4 2 He + 1 0 n + 17.6 MeV

For a nuclear fusion reaction to occur it is necessary to bring two nuclei so close that nuclear forces become active and glue the nuclei together. Nuclear forces are small-distance forces and have to act against the electrostatic forces where positively charged nuclei repel each other. This is the reason why nuclear fusion reactions occur mostly in high density, high temperature environment.

Nuclear fission is the splitting of a massive nucleus into photons in the form of gamma rays, free neutrons, and other subatomic particles. In a typical nuclear reaction involving 235 U and a neutron:

235 92 U + n = 236 92 U followed by 236 92 U = 144 56 Ba + 89 36 Kr + 3n + 177 MeV

For a fission reaction, two conditions need to be satisfied:

1. Critical mass of the substance (the minimum amount of mass is required for fission to be self-sustaining).

2. A relatively slow neutron is required to initiate the process.

 

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Definition:Fission is the splitting of a large atom into two or more smaller ones.Fusion is the fusing of two or more lighter atoms into a larger one.
Natural occurrence of the process:Fission reaction does not normally occur in nature.Fusion occurs in stars, such as the sun.
Byproducts of the reaction:Fission produces many highly radioactive particles.Few radioactive particles are produced by fusion reaction, but if a fission "trigger" is used, radioactive particles will result from that.
Conditions:Critical mass of the substance and high-speed neutrons are required.High density, high temperature environment is required.
Energy Requirement:Takes little energy to split twoatoms in a fission reaction.Extremely high energy is required to bring two or more protons close enough that nuclear forces overcome their electrostatic repulsion.
Energy Released:The energy released by fission is a million times greater than that released in chemical reactions; but lower than the energy released bynuclear fusion.The energy released by fusion is three to four times greater than the energy released by fission.
Nuclearweapon:One class of nuclear weapon is a fission bomb, also known as anatomic bomb or atom bomb.One class of nuclear weapon is thehydrogen bomb, which uses a fission reaction to "trigger" a fusion reaction.

 

1st one nuclear fission & 2nd one nuclear fusion

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Nuclear Fission

Nuclear Fusion

Definition:

Fission is the splitting of a large atom into two or more smaller ones.

Fusion is the fusing of two or more lighter atoms into a larger one.

Natural occurrence of the process:

Fission reaction does not normally occur in nature.

Fusion occurs in stars, such as the sun.

Byproducts of the reaction:

Fission produces many highly radioactive particles.

Few radioactive particles are produced by fusion reaction, but if a fission "trigger" is used, radioactive particles will result from that.

Conditions:

Critical mass of the substance and high-speed neutrons are required.

High density, high temperature environment is required.

Energy Requirement:

Takes little energy to split two atoms in a fission reaction.

Extremely high energy is required to bring two or more protons close enough that nuclear forces overcome their electrostatic repulsion.

Energy Released:

The energy released by fission is a million times greater than that released in chemical reactions; but lower than the energy released by nuclear fusion.

The energy released by fusion is three to four times greater than the energy released by fission.

 

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