Sciencemadness Discussion Board

Electron Capture

Psycho - 17-9-2002 at 20:37

As I was skimming through my General Chemistry book, I cam across a new term, as least new to me. This term is electron capture. The book explains it as the process in which the nucleus captures an inner-shell electron, thereby converting a proton into a neutron. The mass number of the product nucleus is unchnaged, but the atomic number decreases by 1. The conversion of mercury - 179 into gold - 179 is an example. Hmm, by what process can a electron capture occur or is it natural? Also if such an event occurs will the resulting atom be unstable, and revert back to normal or collapse totally into alpha and beta radiation?

Wrong Forum

PrimoPyro - 18-9-2002 at 03:54

This topic is posted in the wrong place. This forum is for discussions regarding the Mad Science bullitin board.

As for your question, that is a secondary form of beta radiation. Electron capture involves expulsion of a positive pion from the atomic nucleus.

As for stability, it depends on the isotope of the compound formed. The majority of these reactions produce atoms with incredibly short half-lives, in the orders of nanoseconds to microseconds usually.

But some are stable. Ive never heard of turning mercury to gold before, sounds like alchemy. I forgot how one calculates the energies involved in these reactions, but its in one of my books.

Lithium compounds have been converted into a variety of atoms. I may post more on this later, as it used to really interest me a long while back.

Electron capture does not invole the absorption of an atom's own electron(s) but rather as radiant beta emissions that collide with the nucleus. As a proton is lost in these reactions, so is a portion of the positive charge of the nucleus, and an electron of lower energy is ejected as a secondary form of beta emission, occurring after the nuclear reaction.

The pions emitted from the nucleus are thought to have a high probability of reacting with an electron before it can exit the electron cloud around the atom, resulting in several possible reactions, ranging from transmutation into neutrons (at very high energies only) to transmutation into neutral pions and positron pairs, which of course annihilate with the nearest electron to excite the nucleus greatly.

Very nteresting reactions, but in general, they are very unpredictable, and are very messy. Never a clean result because of the intense energy densities being worked with, combined with the fact that outside a bubble chamber, one cannot observe direct effects of these reactions. One must use clever mathematics and assumptions to identify what is going on, and only after it has actually occured and past.


Psycho - 18-9-2002 at 03:59

By the Way: All that information was word for word out of my textbook. Thank you for answering my question. Sorry :( Next again I will put my posts in the correct forum.

Psycho - 18-9-2002 at 04:15

What is the quark composition of the pion? Since a pion, is a meson is has a quark and an antiquark. Where did the meson originate? Can you explain the following picture?


sparkgap - 13-3-2005 at 00:25

Basically, the picture wants to say that pion exchange between a proton and a neutron turnes the proton into a neutron and vice versa. Yukawa, IIRC, used the analogy of a bird flying between two nests. This is the "strong force" in effect.

Pions are composed of either an up quark and up antiquark or a down quark and down antiquark (π<sup>0</sup>;), or an up quark and down antiquark (π<sup>+</sup>;).

sparky (^_^)