The f-block of the periodic table of the elements consists of those elements whose atoms or ions have valence electrons in f-orbitals. Actual electronic configurations may be slightly different from what is predicted by the aufbau principle. The elements are also known as inner transition elements. There are two series. Elements of the series in which the electrons are in 4f orbitals belong to the lanthanoid series. Elements of the series in whic...
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The f-block of the periodic table of the elements consists of those elements whose atoms or ions have valence electrons in f-orbitals. Actual electronic configurations may be slightly different from what is predicted by the aufbau principle. The elements are also known as inner transition elements. There are two series. Elements of the series in which the electrons are in 4f orbitals belong to the lanthanoid series. Elements of the series in which the electrons are in 5f orbitals belong to the actinoid series.
All elements in the lanthanide series form M ions. In aqueous solution the early lanthanides are surrounded by 9 water molecules while the later lanthanides have a coordination number of 8. Cerium also forms compounds with the +4 oxidation state; Ce has the very stable electronic configuration of the noble gas Xe. Ce(IV) is a strong oxidising agent. Eu has the configuration [Xe]4f and is a strong reducing agent. The existence of Eu(II) is attributed to the stability of the half...
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