- Europium is a chemical element; it has symbol Eu and atomic number 63. It is a silvery-white metal of the lanthanide 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 Europe. 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 due to their tendency to get oxidised into the more stable +3 state. It has no significant biological role but is relatively non-toxic compared to other heavy metals. Most applications of europium exploit the phosphorescence of europium compounds. Europium is one of the rarest of the rare-earth elements on Earth.
- CSS Hell (csshell.com)
Hello, and welcome to CSS Hell, where you will be subjected to 15 unimaginably torturous CSS puzzles. “What did I do to deserve this?”, you ask. But you know perfectly well: you blashpemized Cascading Style Sheets. I saw that time your friends were complaining about CSS and you piled on with “CSS isn’t even a real programming language”. It is. I saw you upvote that Reddit meme about vertically aligning a div. Just use a flexbox. I saw you chuckle sensibly at those CSS Is Awesome designs. I couldn’t stand to let Håkon Wium Lie’s divine creation be slandered in this way, so I decided to show the nonbelievers like you the wrath of CSS’s unhinged power.