MCQ Detailed View

A fusion nuclear reaction is a type of nuclear process where two or more light atomic nuclei combine or fuse to form a heavier and more stable nucleus, releasing a large amount of energy in the process. This reaction is the opposite of fission, where a heavy nucleus splits into smaller ones.  Definition:

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  Fusion occurs when extremely high temperatures and pressures force nuclei to come close enough to overcome their electrostatic repulsion (since they are both positively charged).

  
  


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  The result is a single heavier nucleus with a slightly lower total mass, and the lost mass converts into energy according to Einstein's equation (E = mc²).

  
  

✅ Examples:

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  In stars: The Sun and other stars produce energy through fusion, where hydrogen nuclei combine to form helium, releasing enormous heat and light.

  
  


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  Hydrogen bomb: A man-made example of an uncontrolled fusion reaction, releasing immense destructive energy.

  
  


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  Future energy source: Scientists are researching nuclear fusion reactors for clean and almost limitless energy on Earth.

  
  

✅ Difference from Fission:

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  Fission: A heavy nucleus (e.g., uranium-235) splits into lighter nuclei, releasing energy.

  
  


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  Fusion: Light nuclei (e.g., hydrogen isotopes) combine to form a heavier nucleus, also releasing energy but with greater efficiency.

  
  

❌ Incorrect Options:

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  Chemical Reaction: Deals with electron interactions, not nuclei.

  
  


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  Nuclear Reaction: A general term, not specific to fusion.

  
  


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  Fission Nuclear Reaction: The opposite process of splitting nuclei.

  
  

✅ Final Answer:

The nuclear reaction where two or more nuclei fuse to form a heavier nucleus is called a Fusion Nuclear Reaction (Option 4).