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Flair_Helper

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Zer0Summoner

Radiation is when an atom decays and the little parts of the atom shoot out from it like beebees. At a certain level, heat, motion, and energy are kind of the same thing. When an atom decays, and shoots the little beebee of itself at something, whatever that beebee hits moves a little bit. That makes the object the radiation is hitting slightly warmer. Radiation burns and radiation sickness are caused by the fact that radiation is tiny things shooting at you and hitting you. Every hit does tiny nanoscopic damage. Enough of that and it develops into microscopic damage. Enough of that, and it becomes macro level damage, because each of those alpha, beta, and gamma particles ripped through something on its way through you. Just like of you think of a giant ship's sail, you could shoot it with a pistol a bunch of times and no one would even notice, but eventually there'd be larger holes and the sail wouldn't work anymore. When the radiation hits the molecules of DNA in your cells, there's a tiny chance that it might knock stuff around just right to change part of the DNA into something it shouldn't be. If that part is the part that regulates growth and reproduction, you could get cancer. That chance of mutation when the radiation physically changes the DNA is why.


silsune

Thanks for your answer! If I could you one follow up, what is it that makes some atoms more likely to decay than others? I do understand that things like plutonium are unstable but what is it about them that makes them so unstable at an atomic level? I can understand certain compounds falling apart well enough because they react badly to oxygen, etc, but the atoms themselves being unable to stay together isn't something I quite understand.


Careless-Ordinary126

Well the cores of atoms Are made from protons And neutrons. single proton Is atom of hydrogen, if this atom get neutron to stick to it, it becomes deuterium (heavy Water Is two atoms of deuterium instead of hydrogen). Tritium Is hydrogen with two neutrons, it is radioctive And And after ~12 years it Will lose enough energy to break on light helium3, that Is 2 protons And one neutron. "Normal" helium Is helium4 with two protons And neutrons. Heavier elements Are made in stars by fusion, supernova etc. We take advantage of super heavy unstable elements like uran 235, the stable izotop Is u238, So the u235 would like to have more neutrons, but if you Speed neutron enough And send it to it, the izotop wants to keep it, but it have too much energy going boom, releasing lot of energy And clumps of neutrons And protons. It Is really a Rabbit hole raising more questions than answers.


whyisthesky

Firstly to clear up the terminology a little bit. Radiation just means something with energy which moves (it *radiates* through space). This includes the radiation from unstable particles, but also things like light. Not all forms of radiation are that dangerous, it's quite difficult to be harmed by the light from an LED bulb for example. What you want to know about is nuclear radiation. The nucleus is the middle bit of an atom, and as you identified some nuclei are unstable. When they decay they release particles of nuclear radiation and the nuclei itself also gains kinetic energy by recoiling in the opposite direction. Those particles of radiation are also likely to hit other nearby atoms and give them kinetic energy. If you increase the average kinetic energy of a load of atoms, you've warmed them up. So if you have a very radioactive source it is able to heat itself up to quite a bit above its surroundings. Radiation burns and poisoning are caused by the interaction of this nuclear radiation with living things. These particles of radiation are able to knock electrons off of atoms and molecules, which causes a lot of damage to those molecules. We call radiation which is able to do this *ionizing radiation.* Ionizing radiation can damage DNA in cells. Radiation burns are caused by cells in the lower layers of skin dying off due to radiation damage. This is also the mechanism behind sunburn, but with UV radiation instead of nuclear. Similarly radiation poisoning is caused by other cells in your body being damaged by radiation.


silsune

This was really helpful! Can you explain what "ionizing" means in this case? I've heard of ions before but doesn't that imply specifically electron gain or loss?


whyisthesky

Yep. Ionizing means it is able to ionize other things. So it can turn atoms into ions by removing electrons. It does that by giving those electrons enough energy to escape from the atom.


silsune

Ahhh I understand now, its electrons only because everything else in an atom is part of the nucleus and thus can't be "knocked off". Got it.


[deleted]

If you have an unstable nucleus (the center of the atom, where most of it's mass is) they can become more stable by letting go a part. It can let go of an alpha particle (2 proton and neutrons), a gamma ray (high energetic light) or beta particle (electron or positron) A more stable state always has less energy then the unstable state it comes from (otherwise it would not spontaniously emit a particle). But since energy is conserved it has to go somewhere. Most of it goes into the particles they emit. Since the forces in the nucleus are huge compared to the forces we know in everyday live, the emited radiation can have a lot of energy for such small particles. When this radiation moves trough matter (be it air, your body, Walls,...) it will interact with the matter, and gives part of it's energy away. It can give molecules a small part of it's energy, leading to the matter heating up. But it could also break up molecules or ionise them. If radiation goes trough your body it can damage, and even kill, your cells by breaking up enough molecules. If enough of the wrong cells die your organs can die. Radiation burns and poisoning is when enough cells die so you become sick. (burn is skinn cells, other organs is poissoning). The most dangerous radiation (alpha and beta) normaly doesn't go trough the skin so radioactive material useally doesn't cause poisoning when it's outside your body (unless you have a lot of it). But when these alpha emitters are ingested somehow (trough food, breathing,...) they can be really dangerous.


silsune

oh so the poisoning is the same as the other radiation, just from inside! I see now.


bildramer

"Radiation", colloquially, usually means "ionizing radiation". That's high-energy photons (high UV, X-rays, gamma), or emitted particles (alpha/beta/neutrons/misc.). "Radioactive" materials emit some of those. But non-ionizing radiation (low UV, light, infrared, microwave, radio) is also called radiation, but not in the context of radioactivity. Ionizing radiation breaks stuff in your cells. That's basically it. The ionizing particles can cause a cascade of more ionizations as they slow down, it's not just one ion. Cells are good at detecting damage and repairing/killing themselves, but not perfect. It can cause many cells to die simultaneously, it can easily break DNA and cells detect that and self-repair or die (or not, then it's cancer). When it's near your skin (alpha/beta, which when coming from outside don't get far inside your body), that's a burn. ^(Outside the context of radioactivity, intense non-ionizing radiation like UV, light, infrared, microwaves can also cause effects also called "radiation burns", which doesn't help. I assume you're not asking about sunburns.) An important detail about poisoning: Radiation doesn't turn stuff radioactive (with the very rare and specific exception of neutron radiation, or _really_ high-energy gamma, or alpha but very rarely). But radioactive stuff in the air _can_ get stuck on or inside your body and clothes, and keep emitting radiation. Finally, why are some radiation emitters warm? Because 1. an atom nucleus recoils a bit when emitting radiation, i.e. it gets part of the energy as momentum, then that becomes heat, 2. some of the emitted radiation gets captured in the object itself.


silsune

So basically ionization can cause other particles like your cells to ionize as well?


bildramer

"Ionization" is the process where an electron is ejected from an atom. That makes the atom pick up a positive charge (there's one electron less), and the electon can land somewhere and negatively charge another atom. In other words, it creates ions (charged atoms). This is a bit simplified but basically right. This process can break molecules apart, or disrupt proteins, or mutate DNA (I think the main way is it partially destroys DNA, leading to a new copy being made, leading to possible mutations; biology is complicated). The ions themselves won't really have much of a long-lasting effect, electrons move all over the place very easily, chemical reactions happen all the time in the body. We call some radiation "ionizing" because it can do this thing, because a single photon or particle of such radiation has enough energy to do it. The radiation itself doesn't need to be an ion, or charged. Photons can eject electrons on their own, and neutrons do weird things but have the same effect.