Element Cobalt, Co, Transition Metal. Have been known for millennia. Glass ingots have been recovered from Egyptian ancientries such as jar dating to the 15. , in coloring of which cobalt salts. Had been used, as well as in the cobalt. Ancient Assyrians and Babylonians used to produce blue paints which were used for ceramics glazing. Contained sapphire was the initial material from which the names of blue paints came.

Element Manganese, Mn, Transition Metal. The element manganese is very closely related to iron. It differs from it in being more readily oxidised, and in its higher compounds being more readily formed than in the case of iron. For the rest, the corresponding compounds of manganese and iron are very similar to one another, and in many cases are isomorphous. In nature, manganese occurs very widely distributed, but is much less abundant than iron. It is found chiefly as manganese peroxide, Mn.

Element Rhodium, Rh, Transition Metal. Was discovered in 1803 by William Hyde Wollaston, soon after his discovery of palladium. Wollaston dissolved raw platinum in aqua regia. The acid surplus was neutralized by caustic soda. He then precipitated the platinum by adding ammonium chloride, NH. Cl; palladium was removed as palladium cyanide after treating the solution with mercuric cyanide.

Element Ruthenium, Ru, Transition Metal. Klaus fused it with saltpeter and isolated the water soluble part. The insoluble part was treated by aqua regia. Then separated the part of crude platinum that was insoluble in aqua regia.

Сергей Есенин по праву считается лучшим поэтом начала ХХ века. Многие его стихи переложены на песни и считаются народными. Почитайте эти стихи и Вы сами поймете почему. ЧТО ПРОШЛО - НЕ ВЕРНУТЬ. Не видать за туманною далью. ВЬЮГА НА 26 АПРЕЛЯ 1912 г. И надо мной звезда горит. Ты плакала в вечерней тишине. Не жалею, не зову, не плачу. Гой, ты, Русь, моя родная. Я снова здесь в семье родной. Не жалею, не зову, не плачу. Никогда я не был на Босфоре.