The chemical symbol for Calcium is Ca and its atomic number is 20.
We find it listed in the periodic table of elements in group 2 and period 4, and block s.
Calcium belongs to the family of alkaline earth metals such as for example Barium, Beryllium, Magnesium, ...
This element is stable.
Caclium as name came from Calx.
Atomic number (Z) 20
Group, block group 2 (alkaline earth metals), s-block
Period: period 4
Element category: alkaline earth metal
Standard atomic weight (±) (Ar): 40.078(4)[2]
Electron configuration: [Ar] 4s2
per shell: 2, 8, 8, 2
Physical properties:
Phase: solid
Melting point: 1115 K (842 °C, 1548 °F)
Boiling point: 1757 K (1484 °C, 2703 °F)
Density near r.t.: 1.55 g/cm3
when liquid, at m.p. 1.378 g/cm3
Heat of fusion: 8.54 kJ/mol
Heat of vaporization: 154.7 kJ/mol
Molar heat capacity 25.929 J/(mol•K)
Atomic properties
Oxidation states: +2, +1, −1 (a strongly basic oxide)
Electronegativity: Pauling scale: 1.00
Ionization energies 1st: 589.8 kJ/mol
2nd: 1145.4 kJ/mol
3rd: 4912.4 kJ/mol
Atomic radius empirical: 197 pm
Covalent radius: 176±10 pm
Van der Waals radius: 231 pm
Crystal structure: face-centered cubic
Speed of sound thin rod 3810 m/s (at 20 °C)
Thermal expansion 22.3 µm/(m•K) (at 25 °C)
Thermal conductivity: 201 W/(m•K)
Electrical resistivity: 33.6 nΩ•m (at 20 °C)
Magnetic ordering: diamagnetic
Young's modulus: 20 GPa
Shear modulus : 7.4 GPa
Bulk modulus: 17 GPa
Poisson ratio: 0.31
Mohs hardness: 1.75
Brinell hardness: 170–416 MPa
CAS Number: 7440-70-2