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  2. Lanthanide contraction - Wikipedia

    en.wikipedia.org/wiki/Lanthanide_contraction

    The lanthanide contraction is the greater-than-expected decrease in atomic radii and ionic radii of the elements in the lanthanide series, from left to right. It is caused by the poor shielding effect of nuclear charge by the 4f electrons along with the expected periodic trend of increasing electronegativity and nuclear charge on moving from left to right.

  3. Lanthanide - Wikipedia

    en.wikipedia.org/wiki/Lanthanide

    All of the lanthanides form Ln 2 Q 3 (Q= S, Se, Te). [18] The sesquisulfides can be produced by reaction of the elements or (with the exception of Eu 2 S 3) sulfidizing the oxide (Ln 2 O 3) with H 2 S. [18] The sesquisulfides, Ln 2 S 3 generally lose sulfur when heated and can form a range of compositions between Ln 2 S 3 and Ln 3 S 4.

  4. Metal ions in aqueous solution - Wikipedia

    en.wikipedia.org/wiki/Metal_ions_in_aqueous_solution

    A metal ion in aqueous solution or aqua ion is a cation, dissolved in water, of chemical formula [M(H 2 O) n] z+.The solvation number, n, determined by a variety of experimental methods is 4 for Li + and Be 2+ and 6 for most elements in periods 3 and 4 of the periodic table.

  5. Rare-earth element - Wikipedia

    en.wikipedia.org/wiki/Rare-earth_element

    The principal sources of rare-earth elements are the minerals bastnäsite (RCO 3 F, where R is a mixture of rare-earth elements), monazite (XPO 4, where X is a mixture of rare-earth elements and sometimes thorium), and loparite ((Ce,Na,Ca)(Ti,Nb)O 3), and the lateritic ion-adsorption clays.

  6. Coordination complex - Wikipedia

    en.wikipedia.org/wiki/Coordination_complex

    Cisplatin, PtCl 2 (NH 3) 2, is a coordination complex of platinum(II) with two chloride and two ammonia ligands.It is one of the most successful anticancer drugs. A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands ...

  7. Glossary of engineering: A–L - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_engineering:_A–L

    Barometer A device for measuring pressure. Battery Electrochemical cells that transform chemical energy into electricity. Base In chemistry, bases are substances that, in aqueous solution, release hydroxide (OH −) ions, are slippery to the touch, can taste bitter if an alkali, [50] change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote ...

  8. Pinacol rearrangement - Wikipedia

    en.wikipedia.org/wiki/Pinacol_rearrangement

    In the absence of trans- alkyl groups, ring contraction may occur as the major product instead, i.e. the ring carbon itself may migrate. [3] [4] This reveals another interesting feature of the reaction, viz. that it is largely concerted. There appears to be a connection between the migration origin and migration terminus throughout the reaction.

  9. Interior product - Wikipedia

    en.wikipedia.org/wiki/Interior_product

    In mathematics, the interior product (also known as interior derivative, interior multiplication, inner multiplication, inner derivative, insertion operator, or inner derivation) is a degree −1 (anti)derivation on the exterior algebra of differential forms on a smooth manifold.