Europium

<p>Europium is a <a href="/facts/Chemical_element/0jducgWD">chemical element</a>; it has <a href="/facts/Symbol_(chemistry)/2Fe1VAL0">symbol</a> Eu and <a href="/facts/Atomic_number/bgAr581S">atomic number</a> 63. It is a silvery-white metal of the <a href="/facts/Lanthanide/rt3XIRCl">lanthanide</a> series that reacts readily with air to form a dark oxide coating. Europium is the most chemically reactive, least dense, and softest of the lanthanides. It is soft enough to be cut with a knife. Europium was discovered in 1896, provisionally designated as Σ; in 1901, it was named after the continent of <a href="/facts/Europe/DTAtrKfh">Europe</a>. Europium usually assumes the <a href="/facts/Oxidation_state/W53W6s6V">oxidation state</a> +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 <a href="/facts/Redox/Pyd5RVcj">reducing</a>. Europium has no significant biological role and is relatively non-toxic compared to other <a href="/facts/Heavy_metal_(chemistry)/Cblmy8qI">heavy metals</a>. Most applications of europium exploit the <a href="/facts/Phosphorescence/WshJFsKV">phosphorescence</a> of europium compounds. Europium is one of the rarest of the <a href="/facts/Rare-earth_elements/PQSUQumk">rare-earth elements</a> on Earth.
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Europium open-in-new

Europium