Electrons in He3

Most recent answer: 10/22/2007

Q:
Just a question about Helium-3 issued from tritium. How many *electrons* does it contain ? If one neutron of the tritium becomes a proton plus an electron *which is emitted*, it remains an Helium-3 nucleus (two protons and one neutron) and ONE electron. Does it mean that this is an ionic form of Helium-3, with a positive charge ?
- Yann
France
A:
Very perceptive of you, Yann!

Tritium decay does in fact produce He3+ ions (the emitted electron escapes too fast to be recaptured). Nonetheless, there are almost always electrons to be had in the environment, and positive ions do not stay that way for long since they attract free electrons. I suppose if a tritium atom decays deep in space far away from other material, it will take a very long time for the He3+ ion to recombine with an electron -- it depends on the environment.

Note -- Tritium decay is accompanied by emission of an electron antineutrino as well, but that’s unimportant for this discussion.

Tom

(published on 10/22/2007)