I've heard an entertaining argument that the answer to your rhetorical question is zero. If there's a heap of sand and someone takes away one grain, there's still a heap of sand. If we repeat this many times, we have a heap of only one grain of sand, then remove that grain and have a heap of sand with no grains of sand left in it.

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Do the decay products even form isolated atoms?

When the radon nucleus splits, do its electrons stick with the smaller nucleuses?

I'd have thought they are ions, which would be likely to bind to molecules in the air before collecting enough free electrons to become an atom.

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That's a fair suggestion. I'll make sure to include mention of dark energy next time.

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Because you are so emphatic in your answer that expansion is not a force that one gets the impression that no such force exists. For example, you quote > You shouldn’t think of galaxies as being pulled apart by some kind of expanding space

and > there is no local effect on particle dynamics from the global expansion of the universe: the tendency to separate is a kinematic initial condition, and once this is removed, all memory of the expansion is lost.

While both sentences are technically correct, a lay person will incorrectly conclude that no local repulsive force exists. I don't think this is good science communication.

Yeah, my furnace filter gets slightly radioactive after a few months. Very minor but it’s detectable above background level.

Ok, so the nomenclature has less to do with the way zooids interact and more to do with their evolutionary history.

That might be oversimplifying things, but I feel like I understand a bit more.

>For the instances where individual molecules are charged, why do they never form ionic bonds as a result of being charged?

They actually do in many cases. For example, a molecule like acetic acid can lose a H+ ion to become acetate, which has a negative charge, and it can form ionic bonds with sodium to form sodium acetate crystals. In these crystals, negatively charged oxygen atoms from the acetate ion are ionically bonded to the positively charged sodium ions. Different crystal structures can form depending on how much water is present.

Isolated pairs of ions don't tend to stay associated in this manner for a variety of reasons (at least in the condensed phase such as an aqueous solution), but as long as they can form a regular lattice with the right energetics, molecules are perfectly capable of forming ionic bonds.

I'm addressing expansion of space because that's the topic of the question. I am confused as to why you think I should answer a different question.

(Regardless, it would seem to me that the appropriate course for you would be to make a separate answer, rather than to falsely claim that the existing answer is incorrect!)

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Of course cosmic expansion does not induce small-scale gravitational repulsion, it's the other way around. It's incomprehensible how can you say that they are not directly linked.

I think you are focussing too much on correcting the misconception that the inertial expansion of the universe is somehow a force pulling things apart, so much that you are ignoring the fact that the cosmological constant is a force pulling things apart that in fact causes the cosmic expansion to accelerate.

A shovel full?

However, there are a lot more more oxygen atoms to collide with. Given mean free path and velocity at standard temperature and pressure, I think the random movement of the Pb atom is more likely to react with oxygen before finding the dust particle. Another response calculated the Pb O reaction to occur with in a second.

There is no way that it is more likely to find other lead atoms, which are only there at trace amounts as decay products, before it interacts with trillions upon trillions of other gas molecules... many of which are reactive.

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Another writer responded with mean free path and velocity for particles. Given that dust, that is other larger masses than individual oxygen atoms, will the electrically charge particle be much more likely to first bound with oxygen and then with dust?

Dark energy's gravity accelerates cosmic expansion. Dark energy also induces small-scale gravitational repulsion. However, we cannot say that cosmic expansion induces small-scale gravitational repulsion, because the two are not directly linked.

That is the claim in the top-level comment: that cosmic expansion does not have a local dynamical influence. This claim remains correct.

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Yes, bioconcentration.

That's amazing about the burning coal mine forming galena from the lead. Nature is incredible.

Wow, so it's biologically concentrating Po-210 like how Chernobyl mushrooms concentrate Cesium-137, or radioactive galena...

This will interest you. Here's a sample of radioactive galena I have from the Kateřina Coal Mine, Radvanice, Czech Republic.

https://youtu.be/Ju8c6LtA5ZE

Here's a close up photo...

https://www.mindat.org/photo-1144820.html

It looks like a bismuth specimen, due to its odd formation process, deposition from hot gas.

The Kateřina Coal Mine was a bizarre combination of a coal and uranium mine, that caught fire in the 1960s or 70s. Fumes from the burning coal seams deposited galena in cracks, which ended up contaminated with radioactive Lead-210, half life 22 years.

The specimen was likely collected in the 1990. The entire site was rehabilitated about 15 years ago, it's now a nice green park. Big difference from the hell scape of a burning radioactive coal mine.