Calcium belongs to the family of elements called the alkaline earth metals. It is placed in Period 4 and Group 2, or the S-block, of the Periodic Table of Elements. It is a soft grey metal with atomic number 20 and weighs 40.078 atomic mass units.
The symbol for calcium is Ca, and it has two valence electrons in the outermost orbit. Its electronic configuration is [Ar] 4S2. It is a solid at room temperature with a melting point of 842 degrees Celsius. Calcium is an essential element required for cellular processes in living things, and it forms a part of bones and teeth. Calcium has a density of 1.54 grams per cubic centimeter.