collision of hydrogen atoms

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Offline Aman Sharma

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collision of hydrogen atoms
« on: 08/05/2012 14:16:13 »
What happens when hydrogen atoms collide under high pressure conditions in the core of a star?
« Last Edit: 08/05/2012 14:18:20 by Aman Sharma »

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Offline CliffordK

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Re: collision of hydrogen atoms
« Reply #1 on: 09/05/2012 00:15:49 »
In the core of a star, one no longer has atoms, but rather plasma, basically ions.

Nuclear Fusion is complicated with the lighter elements.

Looking at the first few elements.

1H (1 proton) (this is the most common form of hydrogen).
2H (Deuterium) (1 proton + 1 neutron)
3H (Tritium) (1 proton + 2 neutrons)

3He (2 protons + 1 neutron)
4He (2 protons + 2 neutrons)

6Li (3 protons + 3 neutrons
7Li (3 protons + 4 neutrons)

Plus, a few additional isotopes which decompose in less than a second.

Potentially 4 hydrogen atoms (protons) (and 2 electrons in the nucleus?) could be simultaneously fused to form 1 helium 4He atom.
However, it may also occur in steps.
1H +1H --> 2H (Deuterium)

Then 1H + 2H --> 3H (or 3He)
or
2H + 2H --> 4He
or
3H + 2H --> 4He + neutron  (this is the reaction that is being attempted in nuclear fusion reactors).

Of course, keeping in mind that in all these reactions, electrons are also being fused into the nucleus, so a proton+electron --> neutron.  And, overall, the charge is conserved, so with 4 hydrogen atoms being fused into a single helium atom, 2 of the electrons end up in the nucleus as part of neutrons, 2 of the electrons remain in the orbital shell.