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  2. Polonium - Wikipedia

    en.wikipedia.org/wiki/Polonium

    A rare and highly radioactive metal (although sometimes classified as a metalloid) with no stable isotopes, polonium is a chalcogen and chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbors in the periodic table: thallium, lead, and bismuth.

  3. List of chemical elements - Wikipedia

    en.wikipedia.org/wiki/List_of_chemical_elements

    Like the periodic table, the list below organizes the elements by the number of protons in their atoms; ... Polonium [cr] 16 6 p-block [209] [a] 9.196: 527:

  4. List of elements by atomic properties - Wikipedia

    en.wikipedia.org/wiki/List_of_elements_by_atomic...

    This is a list of chemical elements and their atomic properties, ordered by atomic number (Z).. Since valence electrons are not clearly defined for the d-block and f-block elements, there not being a clear point at which further ionisation becomes unprofitable, a purely formal definition as number of electrons in the outermost shell has been used.

  5. Electron configurations of the elements (data page) - Wikipedia

    en.wikipedia.org/wiki/Electron_configurations_of...

    Here [Ne] refers to the core electrons which are the same as for the element neon (Ne), the last noble gas before phosphorus in the periodic table. The valence electrons (here 3s 2 3p 3) are written explicitly for all atoms. Electron configurations of elements beyond hassium (element 108) have never been measured; predictions are used below.

  6. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    The periodic table, ... Polonium: Astatine: Radon: Francium: Radium: ... and also changes depending on how many electrons are removed from the atom.

  7. Extended periodic table - Wikipedia

    en.wikipedia.org/wiki/Extended_periodic_table

    The 9s electrons should have ionization energies comparable to those of the 3s electrons of sodium and magnesium, due to relativistic effects causing the 9s electrons to be much more strongly bound than non-relativistic calculations would predict. Elements 165 and 166 should normally exhibit the +1 and +2 oxidation states, respectively ...

  8. Pnictogen - Wikipedia

    en.wikipedia.org/wiki/Pnictogen

    Polonium: Astatine: Radon: ... are the chemical elements in group 15 of the periodic table. ... it leaves two unused electrons in a lone pair unless there is a ...

  9. Thorium - Wikipedia

    en.wikipedia.org/wiki/Thorium

    Polonium: Astatine: Radon: Francium: Radium: Actinium: ... A thorium atom has 90 electrons, ... In the periodic table published by Dmitri Mendeleev in 1869, ...