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Nuclear Power Plant Isar, Germany

Spent nuclear fuel pool

Turbine of a nuclear plant

What Is Radioactivity?

Radioactivity is the spontaneous emission of particles or radiation or both at the same time. These particles and radiation come from the decay of certain nuclides that form them. They disintegrate due to a fix in their internal structure.

What is radioactivity?

Radioactive decay occurs in unstable atomic nuclei. That is, those that do not have enough binding energy to hold the nucleus together.

The decay is a nuclear conversion results in a daughter with a different number of protons or neutrons (or both).  Out of this rule is gamma decay or internal conversion from a nuclear excited state.

There are two types of radioactivity sources: natural and artificial (as the nuclear reactions inside a reactor). The only difference is where they come from. Though, the effects of both radiations are the same.

These sources produce nuclear waste that may emit radiation for billions of years.

This video will help you to understand all those concepts.

What is natural radioactivity?

Naturally occurring radioactive is nuclear decay naturally occurring due to chains of natural elements. It is constantly present in the world.

It can also rise in a focus on natural causes. On example is carbon-14 that is produced in Earth's upper atmosphere. 

It was found out by chance by Henri Becquerel and Marie Curie.

What are the types of radioactivity?

There are three types of emissions: alpha, beta, and gamma rays. Alpha particles are positively charged, beta ones are negative, and gamma rays are neutral.

What is the definition of radioactivity?These types can be condensed in two general types:

  • Electromagnetic radiations (gamma radiation and X-rays)

  • Particulate (beta and alpha radiation).

Each type of emission has different penetrating power in the matter and different ionization energy. They can cause damage to life in different ways.

What are alpha particles?

Alpha particles (or alpha rays) are a form of ionizing high-energy corpuscular radiation. They have little ability to penetrate tissues because they are large.

In alpha decay, an atomic nucleus emits an alpha particle

Alpha rays, due to their positive charge, interact strongly with matter. Thus, they are easily absorbed by the materials. On the other hand, they can travel only a few centimeters in the air.

What are beta particles?

Beta radiation is a form of ionizing radiation emitted by certain types of radioactive nuclei.

During beta decay, when a proton inside a nucleus is converted into a neutron emit a positron.

What are gamma rays?

Gamma rays are as if they were waves. They stabilize the nucleus without changing its proton content. They can penetrate deeper than beta radiation but are less ionizing.

When an excited nucleus emits gamma radiation, neither its mass nor its atomic number varies. It only loses a certain amount of energy.

The daughter nuclei come from alpha and/or beta decay. Alpha or beta decay are generally excited. They emit a gamma-ray photon.

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      Published: December 10, 2009
      Last review: September 27, 2020