I'm reading Richard Rhodes' book on the creation of the atomic bomb, and and we've reached the point of creating Plutonium by bombing U-238 with neutrons. I understand how U-238 absorbs a neutron and turns into U-239, and how beta decay turns the neutron into a proton (92->93 protons), effectively turning it into Neptunium. What I don't understand is if beta decay ejects an electron from the atom, how does the Neptunium get back to an even charge? The additional proton would give it a +1 charge, and the neutron emitted an electron when turning into a proton, so how does the atom go from 92 electrons to 93 electrons?
2
-
3$\begingroup$ I'm not sure where your concern is. There will be positive ions, and electrons zinging around. Sooner or later the electrostatic attraction will be sufficient to bring them together. $\endgroup$– TimWescottCommented May 19, 2023 at 19:39
-
1$\begingroup$ Thanks Tim, that clears things up. The book didn't get into the charge state of the new Nep-239, so I thought I was missing something with the math. The earlier section on beta decay also did not mention (from what I could find) that resulting elements could (would) be ions. $\endgroup$– user367660Commented May 19, 2023 at 19:49
Add a comment
|
1 Answer
$\begingroup$
$\endgroup$
1
What I don't understand is if beta decay ejects an electron from the atom, how does the Neptunium get back to an even charge?
You're confusing chemistry with things nuclear.
Regardless of how many electrons are bound to a nucleus, it's still the same nucleus. One less or one more electron makes no difference.
From a nuclear physics standpoint no one really cares whether the atom gains an electron sooner or later or even never. It could even lose some. That's a fairly trivial detail.
Chemists care about electrons and charge balance, nuclear physics isn't worried. Chemists count electrons, where nuclear physics really cares more about proton and neutron counts.
answered May 19, 2023 at 19:55
-
1$\begingroup$ Excellent answer. One might also consider that uranium metal is, like other metals, well-modeled by a lattice of positive ions immersed in an ocean of conduction electrons. Stealing an electric from that ocean should happen instantaneously. In an insulating uranium compound, the charge transfer might take longer, but it'd still be fast. $\endgroup$– rob ♦Commented May 19, 2023 at 23:54