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  2. Radium - Wikipedia

    en.wikipedia.org/wiki/Radium

    Radium is a chemical element; it has symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) upon exposure to air, forming a black surface layer of radium nitride (Ra 3 N 2).

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

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

    Radioactive isotope table "lists ALL radioactive nuclei with a half-life greater than 1000 years", incorporated in the list above. The NUBASE2020 evaluation of nuclear physics properties F.G. Kondev et al. 2021 Chinese Phys. C 45 030001.

  4. Alkaline earth metal - Wikipedia

    en.wikipedia.org/wiki/Alkaline_earth_metal

    The alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). [1] The elements have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure. [2]

  5. Synthetic element - Wikipedia

    en.wikipedia.org/wiki/Synthetic_element

    The synthetic elements are those with atomic numbers 95–118, as shown in purple on the accompanying periodic table: [1] these 24 elements were first created between 1944 and 2010. The mechanism for the creation of a synthetic element is to force additional protons into the nucleus of an element with an atomic number lower than 95.

  6. 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 ...

  7. Radon-222 - Wikipedia

    en.wikipedia.org/wiki/Radon-222

    In particular, he studied the product in the uranium series, radon-222, which he called radium emanation. [6] In the early 20th century, the element radon was known by several different names. Chemist William Ramsay, who extensively studied the element's chemical properties, suggested the name niton, and Rutherford originally suggested emanation.

  8. Metal toxicity - Wikipedia

    en.wikipedia.org/wiki/Metal_toxicity

    Tl is located on the periodic table near two other highly toxic metals, mercury and lead. Tin poisoning from tin metal, its oxides, and its salts are "almost unknown"; on the other hand certain organotin compounds are almost as toxic as cyanide. Such organotin compounds were once widely used as anti-fouling agents. [33]

  9. Radon - Wikipedia

    en.wikipedia.org/wiki/Radon

    Radon compounds can be formed by the decay of radium in radium halides, a reaction that has been used to reduce the amount of radon that escapes from targets during irradiation. [24] Additionally, salts of the [RnF] + cation with the anions SbF − 6, TaF − 6, and BiF − 6 are known. [24] Radon is also oxidised by dioxygen difluoride to RnF