When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Naturally occurring radioactive material - Wikipedia

    en.wikipedia.org/wiki/Naturally_occurring...

    Naturally occurring radioactive materials (NORM) and technologically enhanced naturally occurring radioactive materials (TENORM) consist of materials, usually industrial wastes or by-products enriched with radioactive elements found in the environment, such as uranium, thorium and potassium and any of their decay products, such as radium and radon. [1]

  3. Natural isotopes - Wikipedia

    en.wikipedia.org/wiki/Natural_isotopes

    Natural isotopes are either stable isotopes or radioactive isotopes that have a sufficiently long half-life to allow them to exist in substantial concentrations in the Earth (such as bismuth-209, with a half-life of 1.9 × 10 19 years, potassium-40 with a half-life of 1.251(3) × 10 9 years), daughter products of those isotopes (such as 234 Th, with a half-life of 24 days) or cosmogenic ...

  4. List of radioactive nuclides by half-life - Wikipedia

    en.wikipedia.org/wiki/List_of_radioactive...

    This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.

  5. List of elements by stability of isotopes - Wikipedia

    en.wikipedia.org/wiki/List_of_elements_by...

    The darker more stable isotope region departs from the line of protons (Z) = neutrons (N), as the element number Z becomes larger. This is a list of chemical elements by the stability of their isotopes. Of the first 82 elements in the periodic table, 80 have isotopes considered to be stable. [1] Overall, there are 251 known stable isotopes in ...

  6. Potassium-40 - Wikipedia

    en.wikipedia.org/wiki/Potassium-40

    Potassium-40 is the largest source of natural radioactivity in animals including humans. A 70 kg human body contains about 140 g of potassium, hence about 140g × 0.0117% ≈ 16.4 mg of 40 K; [ 4 ] whose decay produces about 3850 [ 5 ] to 4300 disintegrations per second ( becquerel ) continuously throughout the life of the person.

  7. Environmental radioactivity - Wikipedia

    en.wikipedia.org/wiki/Environmental_radioactivity

    AGM2015: A worldwide v̄ e flux map combining geoneutrinos from natural Uranium-238 and Thorium-232 decay in the Earth's crust and mantle as well as manmade reactor-v̄ e emitted by power reactors worldwide. Environmental radioactivity is part of the overall background radiation and is produced by radioactive materials in the human environment.

  8. Isotopes of uranium - Wikipedia

    en.wikipedia.org/wiki/Isotopes_of_uranium

    Uranium (92 U) is a naturally occurring radioactive element (radioelement) with no stable isotopes. It has two primordial isotopes, uranium-238 and uranium-235, that have long half-lives and are found in appreciable quantity in Earth's crust. The decay product uranium-234 is also found.

  9. Radon - Wikipedia

    en.wikipedia.org/wiki/Radon

    Natural occurrence: from decay: Crystal structure ... It was the fifth radioactive element to be discovered, after uranium, thorium, radium, and polonium.