Thallium is a chemical element; it has symbol Tl and atomic number 81. It is a gray post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air. Chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861, in residues of sulfuric acid production. Both used the newly developed method of flame spectroscopy, in which thallium produces a notable green spectral line. Thallium, from Greek θαλλός, thallós, meaning "green shoot" or "twig", was named by Crookes. It was isolated by both Lamy and Crookes in 1862; Lamy by electrolysis, and Crookes by precipitation and melting of the resultant powder. Crookes exhibited it as a powder precipitated by zinc at the international exhibition, which opened on 1 May that year.
Cobalt(II) oxide is an inorganic compound that has been described as an olive-green or gray solid. It is used extensively in the ceramics industry as an additive to create blue-colored glazes and enamels, as well as in the chemical industry for producing cobalt(II) salts. A related material is cobalt(II,III) oxide, a black solid with the formula Co3O4.
Thallium(I) chloride, also known as thallous chloride, is a chemical compound with the formula TlCl. This colourless salt is an intermediate in the isolation of thallium from its ores. Typically, an acidic solution of thallium(I) sulfate is treated with hydrochloric acid to precipitate insoluble thallium(I) chloride. This solid crystallizes in the caesium chloride motif.
Thallium(I) fluoride is the inorganic compound with the formula TlF. It is a white solid, forming orthorhombic crystals. The solid is slightly deliquescent. It has a distorted sodium chloride (rock salt) crystal structure, due to the 6s2 inert pair on Tl+.
Bismuth(III) iodide is the inorganic compound with the formula BiI3. This gray-black salt is the product of the reaction of bismuth and iodine, which once was of interest in qualitative inorganic analysis.
Few compounds of californium have been made and studied. The only californium ion that is stable in aqueous solutions is the californium(III) cation. The other two oxidation states are IV (strong oxidizing agents) and II (strong reducing agents). The element forms a water-soluble chloride, nitrate, perchlorate, and sulfate and is precipitated as a fluoride, oxalate or hydroxide. If problems of availability of the element could be overcome, then CfBr2 and CfI2 would likely be stable.
The metallic elements in the periodic table located between the transition metals to their left and the chemically weak nonmetallic metalloids to their right have received many names in the literature, such as post-transition metals, poor metals, other metals, p-block metals and chemically weak metals. The most common name, post-transition metals, is generally used in this article.
Neodymium(III) bromide is an inorganic salt of bromine and neodymium the formula NdBr3. The anhydrous compound is an off-white to pale green solid at room temperature, with an orthorhombic PuBr3-type crystal structure. The material is hygroscopic and forms a hexahydrate in water (NdBr3· 6H2O), similar to the related neodymium(III) chloride.
Dysprosium(III) nitrate is an inorganic compound, a salt of dysprosium and nitric acid with the chemical formula Dy(NO3)3. The compound forms yellowish crystals, dissolves in water, forms a crystalline hydrate.
Polonium tetraiodide is a binary inorganic compound of polonium and iodine with the chemical formula PoI
4. The compound forms volatile black crystals.
Lutetium phosphide is an inorganic compound of lutetium and phosphorus with the chemical formula LuP. The compound forms dark crystals, does not dissolve in water.
Lithium hexafluoroarsenate is an inorganic chemical compound with the chemical formula LiAsF6.
Yttrium perchlorate is the inorganic compound with the chemical formula Y(ClO
4)
3. The compound is an yttrium salt of perchloric acid.
Barium chloride fluoride is an inorganic chemical compound of barium, chlorine, and fluorine. Its chemical formula is BaClF. The compound naturally occurs as zhangpeishanite mineral of the matlockite group. One of the deposits where the mineral is mined is Bayan Obo in China.
Platinum(II) iodide is a binary inorganic compound of platinum and iodine with the chemical formula PtI
2.
Iridium(IV) iodide is a binary chemical compound of iridium and iodide with the chemical formula IrI
4.
Gadolinium(III) nitride is a binary inorganic compound of gadolinium and nitrogen with the chemical formula GdN.
Platinum(IV) iodide is a inorganic compound with the formula PtI4. it is a dark brown diamagnetic solid and is one of several binary iodides of platinum.
Sodium hexafluoroarsenate is an inorganic chemical compound with the chemical formula NaAsF6.
Lithium hexafluorosilicate is an inorganic chemical compound with the chemical formula Li2SiF6.
