O gypsum, Na

Sulfur
Meeting natue. Sulfur is widely distributed in nature. It makes up 0.05% of the mass of the earth's crust. In the free state (yombic sulfur) it is found in large quantities in Italy (on the island of Sicily) and in the USA. There are in Central Asia, Crimea and other regions. Sulfur is often found in the form of compounds formed with other elements. Its most important natural compounds sulfides of metals: FeS₂ - iron colchedane, i.e. pyrite; ZnS- zinc alloy; PbS -lead glitter; HgS - cinnabar and others also salts of sulfuric acid (crystal-hydrates): CaSO₄•2H₂O - gypsum, Na₂SO4•10H₂O - glauber salt, MgSO₄• 7H₂O taxir salt and others Sulfur is in the body of animals and plants, because protein included in the molecules organic compounds of sulfur are present in oil.
Physical properties. Sulfur is a yellow, hard, brittle substance. It is almost insoluble in water, but it is soluble in carbon sulfide, aniline and some other solvents. It does not conduct heat and electricity well.Sulfur undergoes several allotropic form changes. Sulfur boils at 444.6 °C, producing dark brown fumes. If they are cooled quickly, a fine powder of tiny crystals of sulfur is formed, which is called flower of sulfur.
Chemical properties. Because the outer energy level of the sulfur atom is not completed, it can attach two electrons and -2 can represent the oxidation state. Sulfur metals also form compounds with hydrogen (for example, Na₂S and in H₂S) exhibits such an oxidation state. Electrons are transferred to or attracted to an atom of a more electronegative element. Under normal conditions, solid sulfur molecules are connected to each other in the form of rings. It consists of 8 atoms S (where the sulfur atoms in the ring do not lie in the same plane). When heated, the C ring cleaves. At higher temperatures, chain fragments are present. The fact that the physical state of sulfur is different is explained by the structure of its molecule. For example, the reason for the formation of plastic sulfur is that part of the ring-molecules is broken, and the resulting chains join together to form a long chain. as a result, a high molecular compound is formed, an elastic polymer similar to rubber.
Usage. Sulfur is widely used in industry and agriculture. About half of the mined sulfur is used to produce sulfuric acid. Sulfur is used in rubber vulcanization: it increases the fineness and elasticity of rubber. Sulfur in the form of flower of sulfur (fine powder) is used in the fight against vine and cotton diseases. Sulfur is an important element widely used in industry, agriculture and medicine. Considered a mysterious substance since ancient times, sulfur is a fiery and explosive metal that can be used as a powder or liquid. Sulfur, which is very useful for human health, is also the raw material of sulfuric acid, one of the important acids used in industry.