Theoretically, barium-132 can similarly undergo double beta decay to xenon-132 this decay has not been detected. Its abundance is ≈0.1% that of natural barium.
Ba atomic number plus#
Barium-130 undergoes very slow radioactive decay to xenon-130 by double beta plus decay, with a half-life of (0.5–2.7)×10 21 years (about 10 11 times the age of the universe). : 3 Isotopes īarium found in the Earth's crust is a mixture of seven primordial nuclides, barium-130, 132, and 134 through 138. Organobarium compounds are a growing field of knowledge: recently discovered are dialkylbariums and alkylhalobariums. Volatile barium compounds burn with a green to pale green flame, which is an efficient test to detect a barium compound. This property is used in calibrating pH equipment. Unlike calcium hydroxide, it absorbs very little CO 2 in aqueous solutions and is therefore insensitive to atmospheric fluctuations. They are denser than the strontium or calcium analogs, except for the halides (see table zinc is given for comparison).īarium hydroxide ("baryta") was known to alchemists, who produced it by heating barium carbonate. Compounds Selected alkaline earth and zinc salts densities, g/cm 3īarium salts are typically white when solid and colorless when dissolved. Barium combines with several other metals, including aluminium, zinc, lead, and tin, forming intermetallic phases and alloys. Sulfuric acid is a notable exception because passivation stops the reaction by forming the insoluble barium sulfate on the surface.
: 2–3 Reactions with water and alcohols are very exothermic and release hydrogen gas: : 3 Ba + 2 ROH → Ba(OR) 2 + H 2↑ (R is an alkyl group or a hydrogen atom)īarium reacts with ammonia to form complexes such as Ba(NH 3) 6. : 2 Reactions with other nonmetals, such as carbon, nitrogen, phosphorus, silicon, and hydrogen, are generally exothermic and proceed upon heating. For this reason, metallic barium is often stored under oil or in an inert atmosphere. Reactions with chalcogens are highly exothermic (release energy) the reaction with oxygen or air occurs at room temperature. Most exceptions are in a few rare and unstable molecular species that are only characterised in the gas phase such as BaF, : 2 but in 2018 a barium(I) species was reported in a graphite intercalation compound. It is usually found in the +2 oxidation state. : 4–78 Chemical reactivity īarium is chemically similar to magnesium, calcium, and strontium, but even more reactive. : 2 It is a very soft metal with a Mohs hardness of 1.25. : 2Īt room temperature and pressure, barium metal adopts a body-centered cubic structure, with a barium–barium distance of 503 picometers, expanding with heating at a rate of approximately 1.8 ×10 −5/☌. Because barium is difficult to purify, many of its properties have not been accurately determined. Barium has a medium specific weight and high electrical conductivity. : 2 The silvery-white color of barium metal rapidly vanishes upon oxidation in air yielding a dark gray layer containing the oxide. Water-soluble barium compounds are poisonous and have been used as rodenticides.Ĭharacteristics Physical properties Oxidized bariumīarium is a soft, silvery-white metal, with a slight golden shade when ultrapure. In a purer form it is used as X-ray radiocontrast agents for imaging the human gastrointestinal tract.
Barium sulfate is used as an insoluble additive to oil well drilling fluid. Barium compounds are added to fireworks to impart a green color. It is a component of YBCO ( high-temperature superconductors) and electroceramics, and is added to steel and cast iron to reduce the size of carbon grains within the microstructure. Historically, it was used as a getter for vacuum tubes and in oxide form as the emissive coating on indirectly heated cathodes. Barium was identified as a new element in 1772, but not reduced to a metal until 1808 with the advent of electrolysis.īarium has few industrial applications. The name barium originates from the alchemical derivative "baryta", from Greek βαρὺς ( barys), meaning 'heavy'. The most common minerals of barium are baryte ( barium sulfate, BaSO 4) and witherite ( barium carbonate, BaCO 3).
Ba atomic number free#
Because of its high chemical reactivity, barium is never found in nature as a free element. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Barium is a chemical element with the symbol Ba and atomic number 56.
0 kommentar(er)
