eli5 : what is radiation? why is it bad?

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like if things are radioactive what exactly does that mean. is like too much energy coming off? i know it damages our bodies but like how? does it just like kill our cells slowly over time or something?

In: Chemistry

5 Answers

Anonymous 0 Comments

Radioactivity is atoms breaking down because they are unstable. By doing so, they emit high-energy rays (think invisible bullets) that go through your body and break down important things like your DNA. If you’re lucky you’re okay, if there was enough damage your cells might do things like die, stop multiplicating, or be cancerous (multiply like crazy).

That was if you’re hit by radiation. Now if you ingest radioactive elements, it’s as if you had a machinegun inside your body actively shooting you. Pretty bad.

Anonymous 0 Comments

Broadly speaking, radiation refers to any form of energy that is radiated. This includes stuff like visible light. When we talk about the dangerous stuff that you would associate with nuclear waste or atomic bombs, we refer to a category of radiation called ionizing radiation. This radiation consists of subatomic particles that carry enough energy to knock electrons off of atoms. This is potentially bad for us because it can damage the complex molecules, particularly DNA, that our cells depend on. A large dose of radiation can be outright fatal. At lower doses, the damaged DNA can lead to cancer later in life.

There are a few ways of producing ionizing radiation. One way is through radioactive material. When we say something is radioactive, it means the nuclei of its atoms are unstable. Essentially, the nucleus is in a configuration that has too much energy. It shoots out a high-energy particle, changing into a different atom in the process. Until this happens, it behaves like any other atom.

We are constantly exposed to low doses of ionizing radiation from natural sources, including traces of radioactive material in our bodies. It is only at higher doses that you should be concerned.

This chart here is a helpful guide:


Anonymous 0 Comments

Radiation is a bunch of high energy particles.

They have enough energy to break apart molecules, and that’s why it’s dangerous. If it breaks apart enough molecules vital to your cells, the cells die. This causes a radiation burn (like a sun burn), then radiation sickness, then radiation poison, then death.

There are two types, nuclear radiation and electromagnetic radiation.

Electromagnetic radiation, for the most part, isn’t dangerous. This includes radio waves, microwaves, infrared radiation, visible light, UV, xrays, and gamma rays.

Radio waves, microwaves, infrared, and visible light are all perfectly safe because they do not have enough energy to break apart molecules. High enough intensity can cause burns, but not radiation burns. That’s why your microwave oven has a door and your toaster gets hot, but not dangerous on the scale of radiation.

UV light comes in two flavors, UVA and UVB. UVA is safe, UVB is where EM radiation becomes dangerous. This is what is known as ionizing radiation, because it can knock electrons free of atoms, causing the atom to become an ion. This is why it can break apart molecules.

Everything beyond UV is dangerous because it is all higher energy than the UVB we just talked about.

Nuclear radiation includes any subatomic particles ejected from an atomic nucleus at high speeds.

The most common ones are alpha particles, beta particles, and beta plus particles.

Alpha particles (α) are made of 2 protons and 2 neutrons, a helium nucleus, essentially

Beta (β or β-) particles are electrons

Beta plus (β+) particles are positrons (anti electrons)

Proton and nuetron ejection is also possible from a radioactive nucleus, but it’s much more rare than the other 3.

Radioactive decay can also emit a photon, electromagnetic radiation, which we just talked about, but generally in a radioactive substance you’re more worried the particles than the light.

Neutrinos are also emitted as part of Radioactive decay, but they don’t really interact with much. You are bombarded by trillions every day and there’s no way to avoid it, but they don’t do anything, so there’s nothing to worry about.

As far as staying safe from radiation, wear sunscreen and limit your exposure

Anonymous 0 Comments

radiation and radioactivity are different things. Radiation is just the light energy given off by things. But light energy means all forms of light, from microwaves to x rays etc., including visible light. Everything gives off at least some radiation in this way. When people refer to ‘radiation’ as dangerous, they are referring to *ionizing* radiation. This is light rays that are high energy to the point that they can break apart molecules or atoms. If that happens in our bodies, it can do anything from killing cells to causing mutations in DNA that can eventually lead to cancer

Anonymous 0 Comments

Other replies have covered the “tiny bullets” angle, but you also asked about how the damage is done.

There’s two kinds of health effect. The first one is what happens straight away when you get a high dose – this is radiation burns, organ damage, etc. It’s basically those tiny bullets shredding bits of your body so they don’t work any more. If the damage isn’t lethal, it should heal in time.

The second one is called the “stochastic effects”, which means random – because it increases your chance of getting cancer over the long term. Tiny changes in your DNA that might (or might not) cause something to go wrong.

One other thing of note is that some chemicals your body needs in specific small bits of your body – eg, iodine to your thyroid gland.

If you happen to get the radioactive versions of those chemicals in your body, your body can’t tell the difference so effectively creates a concentrated radioactive source inside you.