Radioactive decay, also known as radioactivity, is the process by which a nucleus of an unstable atom loses energy by emitting particles of ionizing radiation. A material that spontaneously emits energetic alpha particles, beta particles, and gamma rays is considered radioactive.

Though the most massive and most energetic of radioactive emissions, the alpha particle is the shortest in range because of its strong interaction with matter. The electromagnetic gamma ray is extremely penetrating, even penetrating considerable thicknesses of concrete. The electron of beta radioactivity strongly interacts with matter and has a short range.

Radioactive material is found throughout nature. Detectable amounts occurs naturally in the soil, rocks, water, air, and vegetation, from which it is inhaled and ingested into the body. The biggest source of natural background radiation is airborne radon, a radioactive gas that emanates from the ground. In addition to this internal exposure, humans are also constantly bombarded by radiation from outer space (Cosmic radiation). Radionuclides can also be produced artificially e.g. using particle accelerators or nuclear reactors.

In my presentation I will show with experiments how radioactivity can be detected and even visualized.