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Q & A: hydrogen neutrality

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Most recent answer: 10/22/2007
Q:
Let’s take hydrogen for my question. H is made up of one proton and one electron. Does that make the atom neutral because the charges cancel each other out. What about the electron’s antiparticle the positron. If there is one electron in the shell, does that mean that there is also one positron? If there is always one positron, then that would cancel out with the electron and the hydrogen atom would have an overall positive charge, right? Thanks!
- Adam (age 15)
Whitmer High School, Toledo, Ohio
A:
Yes, H is neutral because the chrages do cancel out.

No, there's no positron in an H atom. If one was there, temporarily before it either annihilated or left, the resultant object (which would no longre be an H atom) would have positive charge.

Mike W.

You can make "positronium" in the laboratory -- it consists of an electron and a positron which are bound together because of their electrical attraction. It doesn't last too long -- electrons and positrons annihilate quickly.

You can also make "antihydrogen", which is an antiproton with a positron orbiting it. This atom acts, as far as we can tell, just like a hydrogen atom, except the charges are reversed.

I don't think there is a stable bound state of a positron, an electron, and a proton (I could be wrong on this, though).

Tom

(published on 10/22/2007)

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