Proton proton cycle

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Homework Statement



Dear members,
In proton proton cycle, Two protons fuse together to form a duetron with positron and nuetrino.
Then duetron combine with another proton to form 2He3, which then combines with another 2He3 to give 2He4
The final reaction is
41H1+2e---> 2He4

Homework Equations





3. The Attempt at a Solution
Only three protons fuse together in the process, then how in the final equation it has been stated 4 protons fuse. For 2He3 to combine with 2He3 , the reaction of proton fusing with another proton, giving duetron, which fusing with another proton, should happen twice. So it is 6 protons fusing. So why its been mentioned only 4 protons fuse to form helium. Please help revered members

Homework Statement





Homework Equations





The Attempt at a Solution


Homework Statement





Homework Equations





The Attempt at a Solution


Homework Statement





Homework Equations





The Attempt at a Solution


Homework Statement





Homework Equations





The Attempt at a Solution

 

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  • #2
Redbelly98
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3. The Attempt at a Solution
Only three protons fuse together in the process, then how in the final equation it has been stated 4 protons fuse. For 2He3 to combine with 2He3 , the reaction of proton fusing with another proton, giving duetron, which fusing with another proton, should happen twice. So it is 6 protons fusing. So why its been mentioned only 4 protons fuse to form helium. Please help revered members


6 protons fuse to form 2 helium-3 nuclei. Then the two helium-3 nuclei form helium-4 plus 2 protons.

Alternatively, you might write a net reaction that doesn't include 2 of the original 6 protons -- in which case you wouldn't have the 2 protons that are left over in the end.
 
  • #3
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6 protons fuse to form 2 helium-3 nuclei. Then the two helium-3 nuclei form helium-4 plus 2 protons.

Alternatively, you might write a net reaction that doesn't include 2 of the original 6 protons -- in which case you wouldn't have the 2 protons that are left over in the end.
Thanks for the reply sir. But i didnt understand the lines quoted above.
 
  • #4
Redbelly98
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Is this a homework problem? I am having trouble understanding exactly what the problem is asking, or whether you are just trying to understand for yourself what happens in nuclear fusion.
 
  • #5
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Sir, i am asking to get clarified, because my teacher has not given satisfactory reply. I got 90% of what you said, but i cant understand the lines you have written which i quoted in my previous query.
Thanks again. This is the forum which gives excellent insights to physics, thats why i keep raising my query
 
  • #6
Redbelly98
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6 protons fuse to form 2 helium-3 nuclei. Then the two helium-3 nuclei form helium-4 plus 2 protons.
Okay, so omit the intermediate products (He-3 nuclei) and write that as
6 1H → 4He + 2 1H (+ energy, positrons, and neutrinos)
We have hydrogen nuclei on both sides of the reaction, so we can take away 21H from each side. That leaves us with the net reaction.
 
  • #7
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Mr.Redbelly, Fantastic. I got it now. Thank you so much, sir
 

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