Changes

When dealing with beta transformations, one needs to take note of various conservation laws.  (For alpha and gamma transformations, particles don't change, so these issues don't come up.)

When dealing with beta transformations, one needs to take note of various conservation laws.  (For alpha and gamma transformations, particles don't change, so these issues don't come up.)

*Charge - this is the electric charge.  So a neutron, with zero charge, can decay into a proton (+1), and electron (-1), and a neutrino (zero).

*Charge - this is the electric charge.  So a neutron, with zero charge, can decay into a proton (+1), and electron (-1), and a neutrino (zero).

*Baryon number - Baryons are "big" nucleons.  For our purposes, they are protons and neutrons.  They can't just go away.  Nor can the transform into their antiparticles.  (A proton and antiproton annihilating each other would satisfy this, since the baryon numbers are +1 and -1, but that transformation is beyond the scope of this article.)

*Baryon number - Baryons are "big" nucleons.  For our purposes, they are protons and neutrons.  They can't just go away.  Nor can they transform into their antiparticles.  (A proton and antiproton annihilating each other would satisfy this, since the baryon numbers are +1 and -1, but that transformation is beyond the scope of this article.)

*Lepton number.  The lepton numbers can be thought of as "electron-ness", "mu-ness", and "tau-ness".  Electrons and positrons have electron-ness of +1 and -1 respectively (and zero for the other two).  Here is where the neutrinos come into play.  An electron neutrino has an electron-ness of +1, while and anti-neutrino has -1.  That's why the neutron-to-proton-and-electron transformation needs to create the antineutrino to carry off the -1, compensating for the +1 of the electron.

*Lepton number.  The lepton numbers can be thought of as "electron-ness", "mu-ness", and "tau-ness".  Electrons and positrons have electron-ness of +1 and -1 respectively (and zero for the other two).  Here is where the neutrinos come into play.  An electron neutrino has an electron-ness of +1, while and anti-neutrino has -1.  That's why the neutron-to-proton-and-electron transformation needs to create the antineutrino to carry off the -1, compensating for the +1 of the electron.

*Q: How about neutron decay?  How can the closeness of approach be theorized for a single particle?

*Q: How about neutron decay?  How can the closeness of approach be theorized for a single particle?

*A: In such cases it is necessary to consider the more esoteric theory involving quarks, that this article is ignoring for the most part.  In the diagram above, two quarks collided within the neutron, initiating the decay.  One can think of larger particles like neutron as having quarks rattling around inside, ready to collide.

*A: In such cases it is necessary to consider the more esoteric theory involving quarks, that this article is ignoring for the most part.  In the diagram above, two quarks collided within the neutron, initiating the decay.  One can think of larger particles like neutrons as having quarks rattling around inside, ready to collide.

==Half-life==

==Half-life==

Electron capture events are the exception to this.  The probability of an electron capture depends on the availability of electrons in the vicinity of the nucleus.  Things that change the location of electrons can change the radioactive decay rate.

Electron capture events are the exception to this.  The probability of an electron capture depends on the availability of electrons in the vicinity of the nucleus.  Things that change the location of electrons can change the radioactive decay rate.

In fact, if the atom is completely ionized, the electron-capture decay rate essentially goes to zero and the half-life essentially goes to infinity.  Furthermore, the normal beta-minus decay rate can change because it becomes easier for ejected electrons to leave the vicinity of the nucleus.  Ionizing Rhenium-187 has been observed to accelerate its decay by a factor of one billion.<ref>https://creation.com/billion-fold-acceleration-of-radioactivity-demonstrated-in-laboratory billion-fold acceleration of radioactivity demonstrated in laboratory (a creationist website)</ref>

In fact, if the atom is completely ionized, the electron-capture decay rate essentially goes to zero and the half-life essentially goes to infinity.  Furthermore, the normal beta-minus decay rate can change because it becomes easier for ejected electrons to leave the vicinity of the nucleus.  Ionizing Rhenium-187 has been observed to accelerate its decay by a factor of one billion.<ref>https://creation.com/billion-fold-acceleration-of-radioactivity-demonstrated-in-laboratory billion-fold acceleration of radioactivity demonstrated in laboratory (a creationist website)</ref> This effect was produced through the use of a particle accelerator.  It does not occur in nature.

Electron capture events generally involve the innermost electrons, in the "1s" orbital.  Chemical properties (oxidation, reduction, etc.) involve the "valence" electrons in the outermost shell.  So chemical effects on radioactivity are almost never observed.

Electron capture events generally involve the innermost electrons, in the "1s" orbital.  Chemical properties (oxidation, reduction, etc.) involve the "valence" electrons in the outermost shell.  So chemical effects on radioactivity are almost never observed.

But there is a well-known exception to this.  Beryllium, with an atomic number of 4, has only two electrons in the "1s" orbital and two in the "2s" valence orbital.  The latter electrons are so close to the nucleus that chemical changes can have a small but measurable effect on the decay rate.  Beryllium-7 is an electron-capture nucleus, decaying into Lithium-7 with a half-life of 53 days.  This half-life can vary by up to 1.5% due to the chemical state.<ref>https://creation.com/radioactive-decay-rate-depends-on-chemical-environment radioactive decay rate depends on chemical environment (a creationist website)</ref>  Creationist websites often appear to attach great significance to these two situations, even though they do not arise in radiometric dating, perhaps in an attempt to downplay the reliability of radiometric dating.

But there is a well-known exception to this.  Beryllium, with an atomic number of 4, has only two electrons in the "1s" orbital and two in the "2s" valence orbital.  The latter electrons are so close to the nucleus that chemical changes can have a small but measurable effect on the decay rate.  Beryllium-7 is an electron-capture nucleus, decaying into Lithium-7 with a half-life of 53 days.  This half-life can vary by up to 1.5% due to the chemical state.<ref>https://creation.com/radioactive-decay-rate-depends-on-chemical-environment radioactive decay rate depends on chemical environment (a creationist website)</ref>  Creationist websites often appear to attach great significance to this situation and the one described above about Rhenium-187, even though they do not arise in radiometric dating, perhaps in an attempt to downplay the reliability of radiometric dating.

==References==

==References==