Changes

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-plus 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>

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>

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.

==References==

==References==