From the diagram above, the key classifications of Ionizing Radiation are from the Ultraviolet Electromagnetic Waves, to Gamma Electromagnetic Waves.

Now let’s explore together what it means by Ionizing Radiation.

Alpha (α) radiation consists of a fast-moving helium-4 (4He) nucleus and is stopped by a sheet of paper. Beta (β) radiation, consisting of electrons, is halted by an aluminum plate. Gamma (γ) radiation, consisting of energetic photons, is eventually absorbed as it penetrates a dense material. Neutron (n) radiation consists of free neutrons that are blocked by light elements, like hydrogen, which slow and/or capture them. Not shown: galactic cosmic rays that consist of energetic charged nuclei such as protons, helium nuclei, and high-charged nuclei called HZE ions.

Ionizing (or ionising) radiation consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them. The particles generally travel at a speed that is greater than 1% of that of light, and the electromagnetic waves are on the high-energy portion of the electromagnetic spectrum.

Gamma rays, X-rays, and the higher energy ultraviolet part of the electromagnetic spectrum are ionizing radiation, whereas the lower energy ultraviolet, visible light, nearly all types of laser light, infrared, microwaves, and radio waves are non-ionizing radiation. The boundary between ionizing and non-ionizing radiation in the ultraviolet area is not sharply defined because different molecules and atoms ionize at different energies. The energy of ionizing radiation starts between 10 electronvolts (eV) and 33 eV and extends further up.

Typical ionizing subatomic particles include alpha particles, beta particles, and neutrons. These are typically created by radioactive decay, and almost all are energetic enough to ionize. Secondary cosmic particles produced after cosmic rays interact with Earth’s atmosphere, including muons, mesons, and positrons. Cosmic rays may also produce radioisotopes on Earth (for example, carbon-14), which in turn decay and emit ionizing radiation. Cosmic rays and the decay of radioactive isotopes are the primary sources of natural ionizing radiation on Earth, contributing to background radiation. Ionizing radiation is also generated artificially by X-ray tubes, particle accelerators, and nuclear fission.

Ionizing radiation is not detectable by human senses, so instruments such as Geiger counters must be used to detect and measure it. However, very high energy particles can produce visible light, such as in Cherenkov radiation.

Ionizing radiation is used in a wide variety of fields such as medicine, nuclear power, research, and industrial manufacturing, but presents a health hazard if proper measures against excessive exposure are not taken. Exposure to ionizing radiation causes cell damage to living tissue. In high acute doses, it will result in radiation burns and radiation sickness, and lower level doses over a protracted time can cause cancer. The International Commission on Radiological Protection (ICRP) issues guidance on ionizing radiation protection, and the effects of dose uptake on human health.

What we can understand generally is as such, when there exist Ionizing Radiation, there are generally 2 types of ionizing radiation :

Directly Ionizing Radiation and Indirectly Ionizing Radiation.

What we do know is that once the ionizing radiation interacts with a stable atom, due to it’s high energy levels of electromagnetic wave, the gamma photons could have a chance of knocking off a electron from the above said atom, causing it to be in a Ionized state.

In Biology and Chemical Science studies, it is found that when gamma rays managed to ionize the DNA molecular structure, the DNA is permanently damaged, and if it does not repair itself correctly (like a CRC code of a software), it’ll either mutate or remains as a damaged DNA, causing cancerous tumors in various body location, and worst case scenario of propagating this mutated DNA as a hereditary disorder to the next generation.