Eli5 What does radioactive mean?

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It is like light? Or heat or gas? Or small particles like dust? How does it harm us?

In: 3

Radiation is comprised of sub-atomic particles, that being, neutrons and protons and electrons.

They are expelled at insanely high speed from radioactive materials and damage organic tissue by tearing through cells. Think of them as microscopic bullets.

Now, radioactive material, like dust or dirt particles can be ingested and, from there, tear up the human body because those particles will continue to be shot out from the radioactive materials for thousands of years. So, once it’s in you, it’s going to do damage until it’s expelled or you die.

A radioactive atom is unstable. Given time it will either fission — i.e. split in two — or decay, emitting alpha, beta, or gamma radiation.
In the case of fission, the atom becomes two smaller atoms, and possibly one or more neutrons.

Beta particles are electrons; alpha particles are made of two protons and two neutrons, i.e. the nuclei of helium atoms.
Coming out of an atom, alphas, betas, and neutrons are moving at very high speed, so they can do damage to molecules they hit, breaking chemical bonds.

Gammas *are* light, of very high energy. They likewise can do damage.

Radioactive is a term that describes a substance that emits radiation. This can be anything from yellow cake uranium to the potassium 40 in your banana, to the dust made in nuclear fallout.

The next question then is “what is radiation”, which is actually 3 different things.

1. High energy photons, in the form of x rays and gamma rays. They are very dangerous in all circumstances, but not the most common.

2. High speed helium, called alpha particles. They are dangerous if eaten or breathed in large numbers.

3. High speed electrons, called beta particles. These are also dangerous if eaten or breathed.

Everything is made of atoms. Most atoms are stable, and stay what they are forever. The simplest atom is hydrogen, with one proton and one electron. More protons make other atoms. Two protons make helium, six protons make carbon. All atoms more complex than basic hydrogen also contain neutrons, which seem to help those more complex atoms stay stable.

At some point, the balance of forces in an atom, based on how many protons and neutrons they have, just isn’t stable, and there is a chance that the atom will just spontaneously fly apart.

Carbon is a good example. Carbo atoms with 6 protons and 6 neutrons are stable. They stay that way forever, for all intents and purposes. But add two neutrons to a carbon atom, and you get carbon-14, 6 protons and 8 neutrons. That arrangement isn’t stable, and has a 50/50 chance of going wrong about every 6000 years (5730 years, I see when I look it up)

So after 5730 years, half of carbon-14 atoms fall apart and become something else. I really can’t be bothered to look up what they become, because the important part for us here is that when those carbon-14 atoms fall apart, they shoot out a highly energetic particle, and that is where the danger lies.

That highly energetic particle might hit the DNA in one of your cells, and damage it in such a way that your damaged cell becomes a cancer cell.

The danger from carbon-14 is practically zero. The danger from Strontium-90 is huge. Turns out your bones think Strontium-90 is calcium, and knits Strontium-90 right into your bones, where that Strontium-90 shoots high-energy particles into your bone marrow, damages the white blood cells your bone marrow produces, and gives you leukemia.

When Chernobyl melted down in 1986, so much Strontium-90 was released that dairy farmers all over Europe dumped all their milk for months because the milk would have been leukemia in a bottle.

I’m only answering “how does it harm us.” I’m simplifying radiation poisoning in the form of a story. Not too much the science. So yes, it will be *wrong-ish.* If you want the real science ask the other ppl here.

If you pull on a grenade bomb, then leave it in your hands (instead of throwing it far away) it will blow you to bits. If set it down in front of you, it will partially blow you to bits. If you throw it away, but not far enough, you’ll be hit by shrapnel.

I assume you understand atoms make up everything including your cells and the “machinery” inside your cells.

I also assume you know atoms are made up of smaller bits (protons, electrons, neutrons).

So logically, those atomic **bits** are smaller than cells, but more importantly – **smaller than DNA.** Keep these size ratios in mind.

As many people have said radioactive atoms are unstable. In their search for stability, they seprate from each other very quickly. In otherwords, they explode, like a grenade bomb. The difference- in this case, the shrapnel is **the atomic bits.** The insides of the atom are flying at high speed… towards the insides of your cells.

Radioactive poisoning, in a nutshell, is atomic bits blowing your cells and DNA apart. Depending on the type of radiation, the type of cells/DNA, the method you were exposed, and for how long – determines the outcome for you.

Pretty much any degree of this is bad, and typically deadly. “Deadly” just depends on wether you’ll die within hours vs. developing cancer at a mysteriously young age.

Radiation disrupts the rhytms of your body’s complex machinery on such a small scale (literally atomic) that it makes it difficult for traditional medicine to help you.

Even if your cells are mostly intact, even if all it did was cut up your DNA, it has forever messed up your body’s “software code.” You can’t follow instructions that you can’t read.

If the daughters of these “scrambled DNA” cells replicate – you’re spreading this “distorted” software code around your body. Your body is getting more ilegible instructions more often and in more places. This rapidly increases your risk for cancer. Why?

One of these instructions includes suicide. All cells have suicide instructions. A collections of cells that don’t follow instructions and also refuse to die become known as – cancer cells.

Radiation: https://youtu.be/2TxLrfdMKWY

Cancer: https://youtu.be/1AElONvi9WQ

Radiation animation: https://youtu.be/KYDil96NR5Q