Calcium (Ca), 99%, 0.043 gr. - in an ampoule under argon. Articul: 2051131119
Atomic number 20
Atomic mass 40,078
Density, kg / m? < span class = "Apple-tab-span" style = "white-space: pre;"> 1550
melting, ° С 838
Calcium is a soft, reactive alkaline earth metal of a silvery-white color. Ca compounds - limestone, marble, gypsum (as well as lime - a product of limestone burning) were already used in the construction business in ancient times. Until the end of the 18th century, chemists considered lime to be a simple body. In 1789 A. Lavoisier suggested that lime, magnesia, barite, alumina and silica are complex substances. In 1808, G. Davy, subjecting a mixture of wet slaked lime with mercury oxide to electrolysis with a mercury cathode, prepared an amalgam Ca, and after removing mercury from it, he obtained a metal called "Calcium" (from Latin calx, genus calcis - lime) .