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  2. Radioactive decay - Wikipedia

    en.wikipedia.org/wiki/Radioactive_decay

    v. t. e. Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha, beta, and gamma decay.

  3. Background radiation - Wikipedia

    en.wikipedia.org/wiki/Background_radiation

    Background radiation is a measure of the level of ionizing radiation present in the environment at a particular location which is not due to deliberate introduction of radiation sources. Background radiation originates from a variety of sources, both natural and artificial. These include both cosmic radiation and environmental radioactivity ...

  4. Radiation - Wikipedia

    en.wikipedia.org/wiki/Radiation

    Particle radiation from radioactive material or cosmic rays almost invariably carries enough energy to be ionizing. Most ionizing radiation originates from radioactive materials and space (cosmic rays), and as such is naturally present in the environment, since most rocks and soil have small concentrations of radioactive materials.

  5. Electromagnetic radiation - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_radiation

    Classically, electromagnetic radiation consists of electromagnetic waves, which are synchronized oscillations of electric and magnetic fields. In a vacuum, electromagnetic waves travel at the speed of light, commonly denoted c. There, depending on the frequency of oscillation, different wavelengths of electromagnetic spectrum are produced.

  6. Gamma ray - Wikipedia

    en.wikipedia.org/wiki/Gamma_ray

    A gamma ray, also known as gamma radiation (symbol. γ. ), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically shorter than those of X-rays. With frequencies above 30 exahertz (3 × 1019 Hz) and wavelengths less than 10 ...

  7. Earth's internal heat budget - Wikipedia

    en.wikipedia.org/wiki/Earth's_internal_heat_budget

    Earth's internal heat budget is fundamental to the thermal history of the Earth. The flow heat from Earth's interior to the surface is estimated at 47±2 terawatts (TW) [1] and comes from two main sources in roughly equal amounts: the radiogenic heat produced by the radioactive decay of isotopes in the mantle and crust, and the primordial heat ...

  8. Beta particle - Wikipedia

    en.wikipedia.org/wiki/Beta_particle

    Beta radiation, consisting of electrons or positrons, is stopped by a thin aluminum plate, but gamma radiation requires shielding by dense material such as lead or concrete. [1] A beta particle, also called beta ray or beta radiation (symbol β), is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic ...

  9. Cosmic microwave background - Wikipedia

    en.wikipedia.org/wiki/Cosmic_microwave_background

    The cosmic microwave background (CMB, CMBR), or relic radiation, is microwave radiation that fills all space in the observable universe. With a standard optical telescope, the background space between stars and galaxies is almost completely dark. However, a sufficiently sensitive radio telescope detects a faint background glow that is almost ...