Search results
Results from the WOW.Com Content Network
Gallium does not occur as a free element in nature, but rather as gallium(III) compounds in trace amounts in zinc ores (such as sphalerite) and in bauxite. Elemental gallium is a liquid at temperatures greater than 29.76 °C (85.57 °F), and will melt in a person's hands at normal human body temperature of 37.0 °C (98.6 °F).
True chemical analyses were made in the 18th century, [5] and in 1772 Antoine Lavoisier demonstrated that diamond, graphite, and charcoal are all composed of the same substance. [1] In 1787, de Morveau, Fourcroy, and Lavoisier listed carbon (in French, carbone) as an element, distinguishing it from coal (in French, charbon). [1] 29 Copper: 9000 BC
The chemical elements were discovered in identified minerals and with the help of the identified elements the mineral crystal structure could be described. One milestone was the discovery of the geometrical law of crystallization by René Just Haüy , a further development of the work by Nicolas Steno and Jean-Baptiste L. Romé de l'Isle (the ...
Mendeleev later published a theoretical expression of the ether in a small booklet entitled A Chemical Conception of the Ether (1904). His 1904 publication again contained two atomic elements smaller and lighter than hydrogen. He treated the "ether gas" as an interstellar atmosphere composed of at least two elements lighter than hydrogen.
Priestley did not exploit the commercial potential of carbonated water, but others such as J. J. Schweppe made fortunes from it. [83] For his discovery of carbonated water Priestley has been labelled "the father of the soft drink ", [ 84 ] with the beverage company Schweppes regarding him as "the father of our industry". [ 85 ]
Antoine-Laurent de Lavoisier (/ l ə ˈ v w ɑː z i eɪ / lə-VWAH-zee-ay; [1] [2] [3] French: [ɑ̃twan lɔʁɑ̃ də lavwazje]; 26 August 1743 – 8 May 1794), [4] also Antoine Lavoisier after the French Revolution, was a French nobleman and chemist who was central to the 18th-century chemical revolution and who had a large influence on both the history of chemistry and the history of biology.
Davy discovered potassium in 1807, deriving it from caustic potash (KOH). Before the 19th century, no distinction had been made between potassium and sodium. Potassium was the first metal that was isolated by electrolysis. Davy isolated sodium in the same year by passing an electric current through molten sodium hydroxide. [27]
In two papers outlining his "theory of atomicity of the elements" (1857–58), Friedrich August Kekulé was the first to offer a theory of how every atom in an organic molecule was bonded to every other atom. He proposed that carbon atoms were tetravalent, and could bond to themselves to form the carbon skeletons of organic molecules.