Search results
Results from the WOW.Com Content Network
Robert Wilhelm Eberhard Bunsen (German:; 30 March 1811 [a] – 16 August 1899) was a German chemist.He investigated emission spectra of heated elements, and discovered caesium (in 1860) and rubidium (in 1861) with the physicist Gustav Kirchhoff. [11]
Perey discovered it as a decay product of 227 Ac. [177] Francium was the last element to be discovered in nature, rather than synthesized in the lab, although four of the "synthetic" elements that were discovered later (plutonium, neptunium, astatine, and promethium) were eventually found in trace amounts in nature as well. [178]
[3] [7] Francium is the second rarest element (after astatine) — only about 550g exists in the entire Earth's crust at any given time — and it was the last element to be discovered in nature. [ 5 ] [ 6 ] (Five elements that were discovered synthetically were later found to exist in nature: technetium , promethium , astatine , neptunium ...
Today's Game of the Day is crossword heaven! The 100-year-old crossword puzzle just got an update! Daily Celebrity Crossword is the first and only daily crossword puzzle that features the latest ...
Margaret was an only child, born in Berkeley, California to mother Margaret Orchard and father John Melhase, who worked as a geologist. [1] During her time at UC Berkeley, Melhase was a member of the Berkeley Folk Dancers and edited the group's newsletter.
Crossword-like puzzles, for example Double Diamond Puzzles, appeared in the magazine St. Nicholas, published since 1873. [32] Another crossword puzzle appeared on September 14, 1890, in the Italian magazine Il Secolo Illustrato della Domenica. It was designed by Giuseppe Airoldi and titled "Per passare il tempo" ("To pass the time"). Airoldi's ...
Print/export Download as PDF; Printable version; In other projects ... Pages in category "Caesium" The following 7 pages are in this category, out of 7 total.
Discover the best free online games at AOL.com - Play board, card, casino, puzzle and many more online games while chatting with others in real-time.