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]
In vacuum applications, caesium dichromate can be reacted with zirconium to produce pure caesium metal without other gaseous products. [73] Cs 2 Cr 2 O 7 + 2 Zr → 2 Cs + 2 ZrO 2 + Cr 2 O 3. The price of 99.8% pure caesium (metal basis) in 2009 was about $10 per gram ($280/oz), but the compounds are significantly cheaper. [69]
The pure metal was eventually isolated in 1882 by Setterberg. [131] 37 Rubidium: 1861 R. Bunsen and G. R. Kirchhoff: 1863 R. Bunsen Bunsen and Kirchhoff discovered it just a few months after caesium, by observing new spectral lines in the mineral lepidolite. [132] The metal was isolated by Bunsen around 1863. [52] 81 Thallium: 1861 W. Crookes ...
All of the discovered alkali metals occur in nature as their compounds: in order of abundance, sodium is the most abundant, followed by potassium, lithium, rubidium, caesium, and finally francium, which is very rare due to its extremely high radioactivity; francium occurs only in minute traces in nature as an intermediate step in some obscure ...
Francium was discovered by Marguerite Perey [4] in France (from which the element takes its name) on January 7, 1939. [5] Before its discovery, francium was referred to as eka-caesium or ekacaesium because of its conjectured existence below caesium in the periodic table. It was the last element first discovered in nature, rather than by synthesis.
The most reactive metals, such as sodium, will react with cold water to produce hydrogen and the metal hydroxide: 2 Na (s) + 2 H 2 O (l) →2 NaOH (aq) + H 2 (g) Metals in the middle of the reactivity series, such as iron , will react with acids such as sulfuric acid (but not water at normal temperatures) to give hydrogen and a metal salt ...
Caesium-137 (137 55 Cs), cesium-137 (US), [7] or radiocaesium, is a radioactive isotope of caesium that is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclear weapons. Trace quantities also originate from spontaneous fission of uranium-238. It is ...
To give provisional names to his predicted elements, Dmitri Mendeleev used the prefixes eka- / ˈ iː k ə-/, [note 1] dvi- or dwi-, and tri-, from the Sanskrit names of digits 1, 2, and 3, [3] depending upon whether the predicted element was one, two, or three places down from the known element of the same group in his table.