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Germanium did not become economically significant until after 1945 when its properties as an electronic semiconductor were recognized. During World War II, small amounts of germanium were used in some special electronic devices, mostly diodes. [24] [25] The first major use was the point-contact Schottky diodes for radar pulse detection during ...
This page shows the electron configurations of the neutral gaseous atoms in their ground states. For each atom the subshells are given first in concise form, then with all subshells written out, followed by the number of electrons per shell. For phosphorus (element 15) as an example, the concise form is [Ne] 3s 2 3p 3.
Two oxides of germanium are known: germanium dioxide (GeO 2, germania) and germanium monoxide, (GeO). [4] The dioxide, GeO 2 can be obtained by roasting germanium disulfide (GeS 2) or by allowing elemental germanium to slowly oxidze in air, [5] and is a white powder that is only slightly soluble in water but reacts with alkalis to form germanates. [4]
Germanium is usually considered to be a metalloid rather than a metal. [124] Like carbon (as diamond) and silicon, it has a covalent tetrahedral crystalline structure (BCN 4). [125] Compounds in its preferred oxidation state of +4 are covalent. [126] Germanium forms an amphoteric oxide, GeO 2 [127] and anionic germanates, such as Mg 2 GeO 4.
Germanium (32 Ge) has five naturally occurring isotopes, 70 Ge, 72 Ge, 73 Ge, 74 Ge, and 76 Ge. Of these, 76 Ge is very slightly radioactive, decaying by double beta decay with a half-life of 1.78 × 10 21 years [4] (130 billion times the age of the universe). Stable 74 Ge is the most common isotope, having a natural abundance of approximately ...
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The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows (" periods ") and columns (" groups "). It is an icon of chemistry and is widely used in physics and other sciences. It is a depiction of the periodic law, which states that when the elements are arranged in order ...
Eka-tantalum is actually the synthetic superheavy element dubnium (105). Mendeleev's 1869 table had implicitly predicted a heavier analog of titanium (22) and zirconium (40), but in 1871 he placed lanthanum (57) in that spot. The 1923 discovery of hafnium (72) validated Mendeleev's original 1869 prediction. Mendeleev [7] Modern names.