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Proton-Proton Chain


    Stars fuse hydrogen atoms into helium atoms in what's called the proton-proton chain.  A normal hydrogen atom becomes a helium atom and releases a lot of energy in this process.  If you are interested in the more complex physics of stars,


Symbols --

    a proton (positively charged)

    a neutron (like a proton, but has no charge)

    a positron (antimatter, like an electron, but positively charged)

    a neutrino    (subatomic particle, no charge, very low mass)

    a gamma ray    (a form of radiation)


Step 1 --

1H   +   1H   =   2H   +   e +   ν

    Two normal hydrogen atoms collide and produce a heavy hydrogen atom (deuterium), a positiron (the inverse of an electron), and a neutrino.


Step 2 --

1H   +   2H   =   3He   +   γ

    A normal hydrogen atom collides with a deuterium atom and produces a light helium atom and gamma radiation.


Step 3 --

3He   +   3He   =   4He   +   1H   +   1H

    Two light helium atoms collide and produce a normal helium atom and two normal hydrogen atoms.


The Whole Shebang --

6 1H   =   4He   +   2 1H   +   2 e+   +   2 ν   +   2 γ

    One complete fusion reaction takes six normal hydrogen atoms, and spits out a normal helium atom, two normal hydrogen atoms, two positrons, two neutrinos, and gamma radiation.

    For every complete fusion reaction 4.3 x 10-12 joules of energy is produced.  "But when multiplied by the vast number of hydrogen atoms undergoing fusion in the sun, the total energy released is equivalent to exploding 100-billion megaton H-bombs per second!"  Explorations (Thomas Arny)



*Images created by Tiara Norris, August 2004.


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Website last updated March 16,  2006.  Hosted by Anthony Watts, KMXI Radio.  Webmasters Tiara Norris and Brendan Diamond.