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Barium is a chemical element; it has symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. The most common minerals of barium are barite (barium sulfate, BaSO 4) and witherite (barium carbonate ...
This is a list of unsolved problems in chemistry. Problems in chemistry are considered unsolved when an expert in the field considers it unsolved or when several experts in the field disagree about a solution to a problem.
The longest-lived isomer is 133m Ba, which has a half-life of 38.9 hours. The shorter-lived 137m Ba (half-life 2.55 minutes) arises as the decay product of the common fission product caesium-137 . Barium-114 is predicted to undergo cluster decay , emitting a nucleus of stable 12 C to produce 102 Sn.
A mnemonic is a memory aid used to improve long-term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics.
The R block has a chemical formula of Me L Me S 6 O 11 2-. Me L are larger metal cations, for example, alkaline earth metals (Ba, [4] Sr, [5]) rare earth metals, [5] Pb, [6] etc. The point group symmetry of the R block is ¯. The large metal cations are located in the middle layer of the three hexagonally packed layers.
Developments in the field have also resulted in the reduction of the size of Ba-Fe particles to about 20 nm. This contrasts with metal particle technology, which has problems shrinking the particles past 100 nm. [4] Barium ferrite has better packing properties than most other metal particles because of the distinctive shape of the particles. [4]
Barium hydroxide is a chemical compound with the chemical formula Ba(OH) 2. The monohydrate ( x = 1), known as baryta or baryta-water, is one of the principal compounds of barium . This white granular monohydrate is the usual commercial form.
Barium nitrate is the inorganic compound with the chemical formula Ba(NO 3) 2. It, like most barium salts, is colorless, toxic, and water-soluble. It burns with a green flame and is an oxidizer; the compound is commonly used in pyrotechnics. [4]