Radioactivity – The Basics

Energy given off by matter in the form of rays or high-speed particles is known as radiation.

Radioactivity has almost everything to do with atomic structure. An atom consists of the nucleus at its core and the outer shell. The nucleus consists of protons and electrons and the outer shell consists of electrons. Protons have a positive charge; neutrons are neutral, and electrons have a negative charge.

The atom strives towards a balance between the positive and negative charges. Stable atoms have mostly achieved this.

“Heavy” atoms have an instability. Usually because of an overwhelming positive or negative charge. Either way, the atoms try to remove the instability by emission of energy or particles.  This emission is known as radioactive decay. This is usually just referred to as radiation.

Not all radiation is dangerous!

There are two kinds of radiation.

Ionizing radiation is radiation that possesses enough energy to strip particles from an atom. Types of Ionizing radiation include alpha-particles and beta-particles.  This is the more likely to be harmful.

Non-ionizing radiation include radio waves, microwaves, and visible light. So, no, phones will not kill you.

There is a difference between radiation and radioactive material. This is – sadly – often confused by the media, Hollywood, and certain people who should really know better. Radioactive material emits radiation! They are not the same thing!

(Sorry! Sore point.)

Now, let’s talk about different kinds of ionizing radiation.

Alpha-particles are positive-charged particles emitted in the decay of certain radionuclides. It consists of two neutrons and two protons and is identical with the nucleus of the helium atom. These aren’t very harmful and can be stopped by paper. Congratulations to readers for taking precautions.

Beta-particles consist of electrons or positrons. Positrons are usually left out of science classes because they are the antimatter to the electron. They are emitted when a proton turns into a neutron to maintain the atomic balance. Both positrons and electrons can be stopped by an aluminum plate.

Now we get to the radiation everyone is terrified of. Introducing gamma rays! Also known as the radiation that turned Bruce Banner into the Hulk.

(Don’t try that at home, please. It doesn’t work.)

It consists of the shortest wavelength electromagnetic waves, typically shorter than those of X-rays. With frequencies above 30 exahertz (30×10^18 Hz), it imparts the highest photon energy. In other words, it packs a punch. These rays are emitted by nuclear fission. Gamma rays require shielding by extremely dense materials such as lead or concrete. Several meters of it. If you ever wondered why nuclear power stations are so big, this is one of the reasons.

(Not saying nuclear power is a bad source of energy. It’s a long rant if I get started on that so nevermind.)

Those were the absolute basics of radioactivity. Hope I helped!

https://www.nrc.gov/about-nrc/radiation/health-effects/radiation-basics.html

https://www.orau.org/health-physics-museum/basics/index.html

https://www.sciencedirect.com/science/article/abs/pii/S037673610680004X