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Gallium-70 can decay through both beta minus decay and electron capture. Gallium-67 is unique among the light isotopes in having only electron capture as a decay mode, as its decay energy is not sufficient to allow positron emission. [31] Gallium-67 and gallium-68 (half-life 67.7 min) are both used in nuclear medicine.
Gallium was discovered by French scientist Paul-Émile Lecoq de Boisbaudran, who named it in honor of France ("Gallia" in Latin); allegations were later made that he had also named it for himself, as "gallus" is Latin for "le coq", but he denied that this had been his intention. [8]
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]
This is an accepted version of this page This is the latest accepted revision, reviewed on 28 January 2025. 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 extended ...
Its identification was based upon the bright-blue lines in its spectrum, and it was the first element discovered by spectrum analysis. Barium (Ba) 56 βαρύς (barys) Greek via Neo-Latin "heavy" βαρύς (barys) means "heavy". The oxide was initially called "barote", then "baryta", which was modified to "barium" to describe the metal.
Thallium, the heaviest stable element in the boron group, was discovered by William Crookes and Claude-Auguste Lamy in 1861. Unlike gallium and indium, thallium had not been predicted by Dmitri Mendeleev, having been discovered before Mendeleev invented the periodic table. As a result, no one was really looking for it until the 1850s when ...
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.
In 1803 they obtained a white oxide and called it ceria. Martin Heinrich Klaproth independently discovered the same oxide and called it ochroia. It took another 30 years for researchers to determine that other elements were contained in the two ores ceria and yttria (the similarity of the rare-earth metals' chemical properties made their ...