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Calcium
Electron Configuration 2,8,8,2
Electron Configuration [Ar] 4s2
Ground state 1S0
Atomic Volume 29.9 g/cm3
Electronegativity 1.00
Magnetic ordering Paramagnetic
Mass magnetic susceptibility 1.38 x 10-8
Molar magnetic susceptibility 5.531 x 10-10
Speed of sound 3810 m s-1
Thermal Properties
Enthalpy of Atomization 184 kJ mol-1 @25°C
Enthalpy of Fusion 9.33 kJ mol-1
Enthalpy of Vaporisation 150.6 kJ mol-1
Heat Capacity 25.929 J mol-1 K-1
Thermal Conductivity 201 W m-1 K-1
Thermal Expansion 22.3 μm m-1 K-1
Hardness
Brinell hardness 167 MPa
Mohs hardness 1.75
Elastic Properties
Bulk modulus 17 GPa
Poisson ratio 0.31
Shear modulus 7.4 GPa
Young's modulus 20 GPa
Electrical Properties
Electrical resistivity 3.4 x 10-8 Ω m
Electrical conductivity No data.
Chemical Properties
Electrochemical Equivalent 0.7477 g Ah-1
Electron Work Function 2.87 eV
Valence Electron Potential (-eV) 29
Ionization Potential  
First 6.113
Second 11.871
Third 50.908
Incompatibilities Water, oxidizers, acids, air, chlorine, chlorine tri-fluoride (ClF3), fluorine, oxygen, silicon, sulfur.
Flammability
Flammable solid
Energy Levels
Kα1 (intensity 100) 3.69168 KeV
Kα2 (intensity 50) 3.68809 KeV
Kβ1 (intensity 19.52) 4.0127 KeV
Lα1 (intensity 100) 0.3413 KeV
Lα2 (intensity 10) 0.3413 KeV
Lβ1 (intensity 12.3) 0.3449 KeV
Lγ3 (intensity 0) 0.306 KeV
Ll (intensity 100) 0.302 KeV
Atomic Radii
Empirical 180 pm
Bohr Radius 194 pm
Covalent Radius 174 pm
Van der Waals No data.
Triple covalent 133 pm
Metallic 197 pm
Ionic Radii (Å)
Charge Coordination Crystal Ionic Key
VI 1.14 1
VII 1.2 1.06 *
VIII 1.26 1.12 *
IX 1.32 1.18
X 1.37 1.23 C
XII 1.48 1.34 C
R, From r3 vs V plots.
C, Calculated from bond length - bond strength equations.
E, Estimated.
*, Most Reliable.
M, From Metallic Oxides.
A, Ahrens (1952) Ionic radius.
P, Pauling's (1960) Crystal Radius.
Oxidation States
Main Ca+2
Other
Ionisation Energies (kJ mol-1) show graph
M - M+ 589.7
M+ - M2+ 1145
M2+ - M3+ 4910
M3+ - M4+ 6474
M4+ - M5+ 8144
M5+ - M6+ 10496
M6+ - M7+ 12320
M7+ - M8+ 14207
M8+ - M9+ 18191
M9+ - M10+ 20385
Vapour Pressure
P (Pa) 1 10 100 1K 10K 100K
T (K) 864 956 1071 1227 1443 1755
Crystal Structure
Structure Cubic close packed
a = 558.84 pm
b = 558.84 pm
c = 558.84 pm
α = 90°
β = 90°
γ = 90°