DEFINITION: The artifacts and ecofacts used by a group to cope with their physical and social environment. Material culture includes the buildings, tools, and other artifacts that constitute the material remains of a former society -- its technology and artifacts combined.
Calcium 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. The ion Ca 2+ is also the fifth-most-abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate.alcium salts are colorless from any contribution of the calcium, and ionic solutions of calcium (Ca 2+) are colorless as well. As with magnesium salts and other alkaline earth metal salts, calcium salts are often quite soluble in water.
Calcium's atomic weight of 40.078 rounds to a mass number of 40. Subtracting 20 from 40 yields a result of 20. This means an atom with 20 protons and 20 neutrons must be an atom of calcium. In some cases, calcium does not have 20 neutrons.