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Germanium is a chemical element; it has symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid (more rarely considered a metal) in the carbon group that is chemically similar to its group neighbors silicon and tin. Like silicon, germanium naturally reacts and forms ...
Germanium occurs mostly in the oxidation state +4 although many +2 compounds are known. [1] Other oxidation states are rare: +3 is found in compounds such as Ge 2 Cl 6, and +3 and +1 are found on the surface of oxides, [2] or negative oxidation states in germanides, such as −4 in Mg 2 Ge.
Germanium makes up 2 parts per million of the Earth's crust, making it the 52nd most abundant element there. On average, germanium makes up 1 part per million of soil. Germanium makes up 0.5 parts per trillion of seawater. Organogermanium compounds are also found in seawater. Germanium occurs in the human body at concentrations of 71.4 parts ...
Germanium dioxide, also called germanium (IV) oxide, germania, and salt of germanium, [1] is an inorganic compound with the chemical formula Ge O 2. It is the main commercial source of germanium. It also forms as a passivation layer on pure germanium in contact with atmospheric oxygen.
Germanium, antimony and polonium are sometimes also included, although the first two are commonly recognised as metalloids. The p-block metals tend to have structures that display low coordination numbers and directional bonding. Pronounced covalency is found in their compounds; the majority of their oxides are amphoteric. [220]
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 ...
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.
Potassium. Potassium (K) is an alkali metal, underneath sodium and above rubidium, [4] and the first element of period 4. One of the most reactive chemical elements, it is usually found only in compounds. It is a silvery metal [5] that tarnishes rapidly when exposed to the oxygen in air, which oxidizes it.