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Pure germanium is known to spontaneously extrude very long screw dislocations, referred to as germanium whiskers. The growth of these whiskers is one of the primary reasons for the failure of older diodes and transistors made from germanium, as, depending on what they eventually touch, they may lead to an electrical short. [40]
After the Bronze Age, the history of metallurgy was marked by armies seeking better weaponry. States in Eurasia prospered when they made the superior alloys, which, in turn, made better armor and better weapons. [citation needed] The Chinese are credited with the first ever use of Chromium to prevent rusting.
For example, germanium was called eka-silicon until its discovery in 1886, and rhenium was called dvi-manganese before its discovery in 1926. The eka-prefix was used by other theorists, and not only in Mendeleev's own predictions. Before the discovery, francium was referred to as eka-caesium, and astatine as eka-iodine.
This is an accepted version of this page This is the latest accepted revision, reviewed on 17 November 2024. Development of the table of chemical elements The American chemist Glenn T. Seaborg —after whom the element seaborgium is named—standing in front of a periodic table, May 19, 1950 Part of a series on the Periodic table Periodic table forms 18-column 32-column Alternative and ...
1912 – Stainless steel invented by Harry Brearley; 1916 – Method for growing single crystals of metals invented by Jan Czochralski; 1919 – The merchant ship Fullagar has the first all welded hull. 1924 – Pyrex invented by scientists at Corning Incorporated, a glass with a very low coefficient of thermal expansion
The machine used point-contact transistors, made in small quantities by STC and Mullard. These consisted of a single crystal of germanium with two fine wires, resembling the crystal and cat's whisker of the 1920s. These transistors had the useful property that a single transistor could possess two stable states. ...
The Lower Paleolithic period lasted over 3 million years, during which there many human-like species evolved including toward the end of this period, Homo sapiens.The original divergence between humans and chimpanzees occurred 13 (), however interbreeding continued until as recently as 4 Ma, with the first species clearly belonging to the human (and not chimpanzee) lineage being ...
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