Submitted by Sklifosovsky20 t3_yfjvvp in explainlikeimfive
If a nuclear bomb explodes, is stuff in that area radioactive because the bomb’s uranium/plutonium dust is on it or does it actually make everyday atoms in its path radioactive isotopes (like a spoon or apple become inherently radioactive)?
It is kind of both. A nuclear reaction does produce a lot of neutron radiation. This will fuse with other atoms and thorugh neutron activation make these into radioactive isotopes. But this only happens during the nuclear reaction and only in the immediate area around the reaction. So even just a few meters away from the center the neutron activation is quite low.
But all this matter, both fission products and neutron activated isotopes, does get spread around the area and with the wind. And they will blend with the natural elements you find in nature and make things radioactive.
And where should I stand to get superpowers?
Depends what sort of powers you'd like to have.
If you want the power of turning to a gas, I'd recommend standing as close to the explosion as possible.
If you want the power of growing new, exciting things in your body, standing further away will do. You may also pass on these powers to your offspring this way.
The only known powers are the Two Powers you get from nukes. Reasonable.
There is also slowly turning to liquid, by standing somewhere between those two points.
Every cell in your body eventually ruptures. The infamous Third Power that no one talks about because it really is not good!
Stand next to whoever's writing the comic book. If you would like those superpowers to last more than one issue, you may need to find the editors as well.
Yes a nuclear detonation makes other things radioactive. The process is called "neutron activation". Essentially all the high energy particles being flung out from the explosion slam into atoms. The neutrons can be captures in the heavier atoms, mainly in the soil. This creates internal instability in the atom and causes it to become radioactive.
That is what fallout largely is. While most nuclear blasts don't consume all the nuclear material, there really isn't enough to form the dust we get from fallout. That's why if we detonate a bomb high enough over a population there will be little to no radiation damage. A lot of the radiation and danger afterwards come from the neutron activated soils flung into the sky by the blast.
> That is what fallout largely is.
Most of what you've said is right, but this part is not. The most radioactive parts of fallout are fission products, the split "halves" of atoms reacted during the nuclear fission part of the explosion. The reason surface bursts are more dangerous from fallout is not because the dirt itself became neutron activated, but because the fission products mix into the dirt, which makes them fall out of the cloud much sooner than they would otherwise. The mushroom cloud from an air burst is still highly radioactive, it just doesn't (usually) send its products back to the ground very quickly (though there are circumstances in which it could, like if it started raining), and so by the time the radioactive byproducts come back down, they have had some time for the shortest half-lives to burn out, and they are diffused over a larger area (so no single spot on the ground gets too much).
Do you mean the neutrons get conveniently stuck in a heavy atom’s nucleus or do you mean they knock out other neutrons?
Follow-up, if neutrons lack charge then how do neutrons effect how radioactive an atom is?
There's nothing convenient about it. In a nuclear explosion there are trillions of neutrons flying outwards from the epicenter. Through simple statistical probability some will collide with something. Only other radioactive elements would be unstable enough to be fully destroyed by the energy of being slammed into by a neutron. Thus neutrons get stuck inside the nucleus of the atom.
However, without more protons to keep the forces inside the atom balanced it must be released. So the atoms themselves will become radioactive just naturally trying to relieve that imbalance.
Here are some of the radionuclides (atomic isotopes) made by a nuclear explosion.
Neutrons attach to atomic nuclei and transform them into other elements by literally slamming into the nucleus. It's not really about convenience, even a 0.00001% chance of a neutron hitting an atom just right to transform it is inevitable when we talk about the number of atoms in a given volume. The molar mass for atmospheric oxygen (2 oxygen atoms) is about 32 grams. 6 x 10^23 molecules of O2 weighs 32 grams. There's a lot of atoms around a nuclear explosion taking place on earth.
Any atom can be radioactive, they do not need to be heavy. Tritium for example is a radioactive form of hydrogen with 2 neutrons. Hydrogen is stable and not radioactive with 1 or 2 neutrons. There's generally a ratio between neutrons and protons (really simplifying this) where elements tend to be stable. Go outside of that ratio and the element tends to be unstable and will decay into something else. The why is related to quantum mechanics.
> Hydrogen is stable and not radioactive with 1 or 2 neutrons.
You meant 0 or 1 neutrons.
Why would a neutron get stuck in the nucleus instead of bouncing off?
Neutrons don't have an electric charge, so they are not repelled by the negative electrons around the atom, or the positive protons in the nucleus. The strong nuclear force (which is much stronger than other forces, hence the name) holds protons and neutrons together in the nucleus, and keeps the new neutron there instead of it "bouncing" off.
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restricteddata t1_iu4arbs wrote
A nuclear explosion creates several kinds of radioactive atoms:
Any atoms that get split during nuclear fission will be radioactive — some extremely radioactive, some less so. These "fission products" make up the most radioactive byproducts of a nuclear explosion and are what we care the most about from a health perspective.
Any fuel atoms (plutonium or uranium) that don't get fissioned will still be around, and are still radioactive (but not that radioactive compared to the other things on here — they have relatively long half-lives).
Some fuel atoms (plutonium or uranium) will absorb neutrons and not fission, becoming heavier atoms, which are also radioactive. This is not a huge issue, but I'm just pointing it out for completeness.
Atoms in the bomb or the environment which absorb neutrons can become artificially radioactive. This is called neutron activation. Depending on the atom in question, it might be only a little radioactive, or very radioactive. The health consequences can vary depending on the elements in question.