- The Bonneville flood was a catastrophic flooding event in the last ice age, which involved massive amounts of water inundating parts of southern Idaho and eastern Washington along the course of the Snake River. Unlike the Missoula Floods, which also occurred during the same period in the Pacific Northwest, the Bonneville flood happened only once.
- Europium (Wikipedia)
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.