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Europium usually assumes the oxidation state +3, like other members of the lanthanide series, but compounds having oxidation state +2 are also common. All europium compounds with oxidation state +2 are slightly reducing. Europium has no significant biological role and is relatively non-toxic compared to other heavy metals.
Europium(II) sulfate is the sulfate of divalent europium, which can be obtained by electrolysis of europium sulfate solution with mercury as the cathode, or by reducing europium(III) chloride with zinc amalgam, and then reacting with sulfuric acid. [50]
Phosphorescent materials were discovered in the 1700s, and people have been studying them and making improvements over the centuries.The development of strontium aluminate pigments in 1993 was spurred on by the need to find a substitute for glow-in-the-dark materials with high luminance and long phosphorescence, especially those that used promethium.
Some compounds are toxic; [11] the metal is highly toxic to viruses. [40] dysprosium: 66: 2: Has no known biological role. [11] Some salts have low toxicity. [41] erbium: 68: 2a: Has no known function in humans, and is not taken up by plants. [11] Soluble salts are mildly toxic. [41] europium: 63: 2a: Has no known function in humans, and is not ...
Europium is exempt of this classification as it has two valence states: Eu 2+ and Eu 3+. [29] Yttrium is grouped as heavy rare-earth element due to chemical similarities. [30] The break between the two groups is sometimes put elsewhere, such as between elements 63 (europium) and 64 (gadolinium). [31]
(Reuters) - Rare earth metals are making headlines as demand rises for products from smartphones to wind turbines, and as governments seek secure supply.
Europium(II) sulfide is the inorganic compound with the chemical formula EuS. It is a black, air-stable powder . Europium possesses an oxidation state of +II in europium sulfide, whereas the lanthanides exhibit a typical oxidation state of +III. [ 1 ]
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