Переведите письменно на английский язык, используя текст. 1.Что ты знаешь о металлах, используемых в промышленности? 2.Металлы, существующие в элементарной форме – медь, золото, серебро, платина. 3.Такие металлы, как железо, медь, цинк были использованы человечеством. Metals In general metals are solids with a metallic lustre, conductors of electricity, malleable, and of high physical strength. In compound form, the metals have positive valences. Probably, their most important characteristic is that when used аs a metal they are usually in elemental form or alloyed with other metals. The metals long used by mankind - iron, copper, zinc, mercury, silver and gold - are those which exist as easily recognized minerals in large deposits and which are easily reduced from compounds to elemental forms. The most important metal, iron, is both prevalent and easily reduced to metallic form. In more recent times some of the most naturally prevalent metals that are difficult to reduce have become common and readily available due to the development of electrochemical processes for their production. These include aluminium, magnesium and sodium. The metals occur most commonly as oxides or sulphides in ores that contain such materials as clay, silica, granite, etc. from which the metal compounds must be separated. Since only a few of the metals, such as copper, gold, silver, platinum and bismuth exist in elemental form, the chief problem is that of reducing them from compound to elemental form.