Michael – just to recap:
Earlier, when expressing your doubts about the reliability of dating things using radioactive decay, you said:
In response to your implying that we must live long enough to see half of the sample decay before we can test the half-life method, I explained that it is not at all necessary to wait for half of the sample to decay in order to determine the half-life.
In response, rather than directly admitting your understanding of how half-life is determined was incorrect, you opted to basically ignore that and try and toss some other issues into the fray:
This type of response is one reason why it is a tad embarrassing even trying to have an intelligent conversation with you. If you were some kid approaching your teen-age years, it would be far more understandable. But for someone who repeatedly claims an understanding of science <half-lives obviously an exception>, you even assert:
I had never realized that the archangel Michael was a high-school dropout. Is your sharing the same name as the archangel a subtle hint that you are actually one and the same?
Anyway, let me take a few minutes and share some info on radioactive decay. (Feel free to share this with your angel buddy namesake.)
Semtex is a plastic explosive widely used in both industry and by the military. You definitely don’t want to be close to it when it is detonated. It is primarily composed of carbon, hydrogen, nitrogen, and oxygen. Now – a thought experiment. Imagine we attach a little teeny label on every single atom in a block of semtex. Each label has a unique number, along with the symbol for the name of the atom it is attached to (C or O or N or H). Our objective will be to see what happens to the atoms as a result of the detonation.
Now we put in a detonator, get a long ways away, and set it off. A big flash of light, junk flying everywhere, massive destruction, a deafening boom. Now we send some lackeys (grad students) out to document what happened to every one of those labelled semtex atoms. Years later, when the last grad student has successfully reported back, we compile our data, and viola, big surprise (surprise only to a creationist), every single atom of carbon is still just an atom of carbon, every oxygen atom is still around, and nitrogen, and hydrogen. In spite of all of these atoms being part of a horrific explosion, not a one of them was fundamentally changed. They are no longer in the semtex. Some of the hydrogen and oxygen atoms have now gone on to form water molecules, and some of the carbon atoms were taken up by nearby foliage, and nitrogen just joined the nitrogen already in the atmosphere.
Ionic bonding, and covalent bonding (remember those terms from your chem classes?) Ionic and covalent bonding describe the ways the electrons in the atoms attach to other atoms. For reasons I haven’t got time to go into here, suffice it to say that in some chemical compounds the electrons are pretty firmly attached where they are, yet there are changes (rearrangements of the atoms and bonding) that could be made resulting in a much tighter attachment of the electrons to the atoms they are with. That’s what happens when semtex explodes – it is safe to handle because the electrons are firmly attached where they are, yet if given a strong boost, the electrons and atoms can start rearranging into a much lower-energy configuration, releasing a whole lot of the excess energy in the process. The detonator provides the initial boost to start that rearrangement. Once it starts, the energy released by the first atoms and electrons provides plenty of energy for the next layer of atoms and electrons to rearrange, and a split second later, they are all done, with lots of the former H and O atoms now in lower energy H2O molecules, and N atoms in N2 molecules, etc, with the whole hot mass expanding out in the form of an explosion.
Where am I going with this? You mention gases mixing in with the radioactive sample altering the radioactive decay. Just as the impressive energy in plastic explosives comes from nothing more than changing the way the orbital electron energies are distributed, so also any introduction of gases, water, contaminants, etc, will do no more than allow the atoms to perhaps join into new and different molecules. (In fact this was one of the techniques proposed to separate radioactive uranium atoms from stable uranium atoms for the first atomic bomb. The two types of uranium atoms have slightly different atomic weights, so when combined with oxygen they form gas molecules that are of two slightly different weights. Fill a long tube with cotton, then put the gas mixture in one end. The lighter molecules will be bouncing around very slightly faster than their beefier brothers, and will find their way through the maze of cotton fibers more quickly. The first gas atoms to come out the other end of the tube will be more enriched in one of the types of uranium than the other. Finally, chemically strip off the oxygen atoms to recover the enriched radioactive uranium metal.)
I know this is a lot of stuff, but there is one more crucial thing to understand, and everything I have described above is just a prelude. Radioactive decay is a nuclear process. It is not involved with the electrons orbiting the atoms – the ionic or the covalent bonding. It involves forces unique to the nucleus, forces which are vastly more powerful than those seen in the semtex explosion. Screwing around with the electrons in orbit around the atoms has almost no effect on what is happening in the nucleus. That is why you use semtext (or something equivalent) to blow up an enemy building (using changes in ionic and covalent boding energies), but when you release a small fraction of the energy in the nucleus in a weapon, you assure that tears will flow for many decades at the memorial in Peace Park in Hiroshima. (I have been there a number of times. And cried.)
Summary – if you are not materially altering the nuclear energies, and you are speaking of reactions involving only orbital electrons, then you are not going to have much effect on decay rates.