Calcium metal is a chemical element with symbol Ca and atomic number 20. Calcium is a soft gray alkaline earth metal, fifth-most-abundant element by mass in the Earth's crust. It is essential for living organisms, in particular in cell physiology, where movement of the calcium ion into and out of the cytoplasm functions as a signal for many cellular processes. As a major material used in mineralization of bone, teeth and shells, calcium are the most abundant metal by mass in many animals.
The electrolytic method is based on the electrolytic separation of calcium from its chloride on the copper-calcium cathode, followed by distillation of calcium from the alloy.