Calcium

Calcium (Ca)

Soft grey metallic element belonging to group 2 of the periodic table. Used a reducing agent in the extraction of thorium, zirconium and uranium. Essential element for living organisms.
Atomic Number20
Atomic Weight40.078
Mass Number40
Group2
Period4
Blocks
Protons20 p+
Neutrons20 n0
Electrons20 e-
Calcium 1.jpg Animated Bohr Model of Ca (Calcium) Enhanced Bohr Model of Ca (Calcium) Bohr Model: Ca (Calcium) Orbital Diagram of Ca (Calcium)

Properties

Atomic Radius
180 pm
Molar Volume
Covalent Radius
171 pm
Metallic Radius
174 pm
Ionic Radius
100 pm
Crystal Radius
114 pm
Van der Waals Radius
231 pm
Density
1.54 g/cm³
Energy
Proton Affinity
Electron Affinity
0.02455 eV/particle
Ionization Energy
6.1131552 eV/particle
Heat of Vaporization
153.6 kJ/mol
Heat of Fusion
9.2 kJ/mol
Heat of Formation
177.8 kJ/mol
Electrons
Electron Shells2, 8, 8, 2
Valence Electrons2
Electron Configuration[Ar] 4s2
Oxidation States1, 2
Electronegativity
1
Electrophilicity
0.7734001442996138 eV/particle
Phases
PhaseSolid
Gas Phase
Boiling Point
1,757.15 K
Melting Point
1,115.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Color
Silver
Appearance
Refractive Index
Thermodynamic Properties
Thermal Conductivity
Thermal Expansion
0.0000223 1/K
Molar Heat Capacity
25.929 J/(mol K)
Specific Heat Capacity
0.647 J/(g⋅K)
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
TypeConductor
Electrical Conductivity
29 MS/m
Electrical Resistivity
0.00000003399999999999 m Ω
Superconducting Point
Magnetism
Typeparamagnetic
Magnetic Susceptibility (Mass)
0.0000000138 m³/Kg
Magnetic Susceptibility (Molar)
0.0000000005531 m³/mol
Magnetic Susceptibility (Volume)
0.00002139
Magnetic Ordering
Curie Point
Neel Point
Structure
Crystal StructureFace Centered Cubic (FCC)
Lattice Constant
5.58 Å
Lattice Anglesπ/2, π/2, π/2
Mechanical Properties
Hardness
1.75 MPa
Bulk Modulus
17 GPa
Shear Modulus
7.4 GPa
Young Modulus
20 GPa
Poisson Ratio
0.31
Speed of Sound
3,810 m/s
Classification
CategoryAlkaline earth metals, Alkaline earth metals
CAS GroupIIA
IUPAC GroupIIA
Glawe Number16
Mendeleev Number7
Pettifor Number16
Geochemical Classmajor
Goldschmidt Classlitophile
Other
Gas Basicity
Dipole Polarizability
160.8 ± 4 a₀
C6 Dispersion Coefficient
2,163 a₀
Allotropes
Neutron Cross Section
0.43
Neutron Mass Absorption
0.00037
Quantum Numbers1S0
Space Group225 (Fm_3m)

Isotopes of Calcium

Stable Isotopes6
Unstable Isotopes23
Radioactive Isotopes22

33Ca

Abundance
Relative Atomic Mass
33.033312 ± 0.000429 Da
Mass Number33
G-Factor
Half Life
Spin5/2
Quadrupole Moment
Discovery Year
Parity+

33Ca Decay Modes
Decay ModeIntensity
p (proton emission)%

34Ca

Abundance
Relative Atomic Mass
34.015985 ± 0.000322 Da
Mass Number34
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year
Parity+

34Ca Decay Modes
Decay ModeIntensity
2p (2-proton emission)%

35Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
35.005572 ± 0.000215 Da
Mass Number35
G-Factor
Half Life
25.7 ± 0.2 ms
Spin1/2
Quadrupole Moment
0
Discovery Year1985
Parity+

35Ca Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)95.8%
2p (2-proton emission)4.2%

36Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
35.993074388 ± 0.000042941 Da
Mass Number36
G-Factor
0
Half Life
100.9 ± 1.3 ms
Spin0
Quadrupole Moment
0
Discovery Year1977
Parity+

36Ca Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)51.2%

37Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
36.985897849 ± 0.00000068 Da
Mass Number37
G-Factor
Half Life
181 ± 0.9 ms
Spin3/2
Quadrupole Moment
Discovery Year1964
Parity+

37Ca Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)76.8%

38Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
37.976319223 ± 0.000000208 Da
Mass Number38
G-Factor
0
Half Life
443.7 ± 0.25 ms
Spin0
Quadrupole Moment
0
Discovery Year1966
Parity+

38Ca Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

39Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
38.970710811 ± 0.00000064 Da
Mass Number39
G-Factor
0.68093333333333 ± 0.00010666666666667
Half Life
860.3 ± 0.8 ms
Spin3/2
Quadrupole Moment
0.038 ± 0.003
Discovery Year1943
Parity+

39Ca Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

40Ca

Abundance
96.941 ± 0.156
Relative Atomic Mass
39.96259085 ± 0.000000022 Da
Mass Number40
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1922
Parity+

40Ca Decay Modes
Decay ModeIntensity
+ (double β+ decay)%

41Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
40.962277905 ± 0.000000147 Da
Mass Number41
G-Factor
Half Life
99.4 ± 1.5 ky
Spin7/2
Quadrupole Moment
-0.0665 ± 0.0018
Discovery Year1939
Parity-

41Ca Decay Modes
Decay ModeIntensity
ϵ (electron capture)100%

42Ca

Abundance
0.647 ± 0.023
Relative Atomic Mass
41.95861778 ± 0.000000159 Da
Mass Number42
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1934
Parity+

43Ca

Abundance
0.135 ± 0.01
Relative Atomic Mass
42.958766381 ± 0.000000244 Da
Mass Number43
G-Factor
-0.37638 ± 0.000017142857142857
Half Life
Spin7/2
Quadrupole Moment
-0.0408 ± 0.0008
Discovery Year1934
Parity-

44Ca

Abundance
2.086 ± 0.11
Relative Atomic Mass
43.955481489 ± 0.000000348 Da
Mass Number44
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1922
Parity+

45Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
44.95618627 ± 0.000000392 Da
Mass Number45
G-Factor
-0.37897142857143 ± 0.00037142857142857
Half Life
162.61 ± 0.09 d
Spin7/2
Quadrupole Moment
0.038 ± 0.012
Discovery Year1940
Parity-

45Ca Decay Modes
Decay ModeIntensity
β (β decay)100%

46Ca

Abundance
0.004 ± 0.003
Relative Atomic Mass
45.953687726 ± 0.000002398 Da
Mass Number46
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1938
Parity+

46Ca Decay Modes
Decay ModeIntensity
(double β decay)%

47Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
46.954541134 ± 0.000002384 Da
Mass Number47
G-Factor
-0.40182857142857 ± 0.00031428571428571
Half Life
4.536 ± 0.003 d
Spin7/2
Quadrupole Moment
0.084 ± 0.006
Discovery Year1951
Parity-

47Ca Decay Modes
Decay ModeIntensity
β (β decay)100%

48Ca

AbundanceRadioactive ☢️
0.187 ± 0.021
Relative Atomic Mass
47.952522654 ± 0.000000018 Da
Mass Number48
G-Factor
0
Half Life
56 ± 10 Ey
Spin0
Quadrupole Moment
0
Discovery Year1938
Parity+

48Ca Decay Modes
Decay ModeIntensity
(double β decay)%
β (β decay)%

49Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
48.955662625 ± 0.00000019 Da
Mass Number49
G-Factor
-0.91993333333333 ± 0.00053333333333333
Half Life
8.718 ± 0.006 m
Spin3/2
Quadrupole Moment
-0.036 ± 0.003
Discovery Year1950
Parity-

49Ca Decay Modes
Decay ModeIntensity
β (β decay)100%

50Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
49.957499215 ± 0.0000017 Da
Mass Number50
G-Factor
0
Half Life
13.45 ± 0.05 s
Spin0
Quadrupole Moment
0
Discovery Year1964
Parity+

50Ca Decay Modes
Decay ModeIntensity
β (β decay)100%

51Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
50.960995663 ± 0.00000056 Da
Mass Number51
G-Factor
-0.69973333333333 ± 0.00073333333333333
Half Life
10 ± 0.8 s
Spin3/2
Quadrupole Moment
0.036 ± 0.012
Discovery Year1980
Parity-

51Ca Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%

52Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
51.963213646 ± 0.00000072 Da
Mass Number52
G-Factor
0
Half Life
4.6 ± 0.3 s
Spin0
Quadrupole Moment
0
Discovery Year1985
Parity+

52Ca Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)2%

53Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
52.968451 ± 0.000047 Da
Mass Number53
G-Factor
Half Life
461 ± 90 ms
Spin1/2
Quadrupole Moment
0
Discovery Year1983
Parity-

53Ca Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)40%

54Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
53.972989 ± 0.000052 Da
Mass Number54
G-Factor
0
Half Life
90 ± 6 ms
Spin0
Quadrupole Moment
0
Discovery Year1997
Parity+

54Ca Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

55Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
54.979978 ± 0.000172 Da
Mass Number55
G-Factor
Half Life
22 ± 2 ms
Spin5/2
Quadrupole Moment
Discovery Year1997
Parity-

55Ca Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

56Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
55.985496 ± 0.000268 Da
Mass Number56
G-Factor
0
Half Life
11 ± 2 ms
Spin0
Quadrupole Moment
0
Discovery Year1997
Parity+

56Ca Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

57Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
56.992958 ± 0.000429 Da
Mass Number57
G-Factor
Half Life
Spin5/2
Quadrupole Moment
Discovery Year2009
Parity-

57Ca Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

58Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
57.998357 ± 0.000537 Da
Mass Number58
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year2009
Parity+

58Ca Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

59Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
59.006237 ± 0.000644 Da
Mass Number59
G-Factor
Half Life
Spin5/2
Quadrupole Moment
Discovery Year2018
Parity-

59Ca Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

60Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
60.011809 ± 0.000751 Da
Mass Number60
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year2018
Parity+

60Ca Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

61Ca

AbundanceRadioactive ☢️
Relative Atomic Mass
61.020408 ± 0.000859 Da
Mass Number61
G-Factor
Half Life
Spin1/2
Quadrupole Moment
0
Discovery Year
Parity-

61Ca Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

History

Calcium was known as early as the first century when the Ancient Romans prepared lime as calcium oxide. Calcium was first isolated by Sir Humphry Davy in 1808 when he electrolyzed a mixture of lime and mercuric oxide. Davy was trying to isolate calcium; when he heard that Jöns Jakob Berzelius and Pontin prepared calcium amalgam by electrolyzing lime in mercury, he tried it himself. From the Latin word calx, lime

DiscoverersSir Humphrey Davy
Discovery LocationEngland
Discovery Year1808
Etymology (Name Origin)Latin: calx, calcis (lime).
PronunciationKAL-si-em (English)
Calcium is considered to be non-toxic
The shell of an egg is made up of primarily calcium carbonate

Uses

Calcium is used to remove oxygen, sulfur and carbon from alloys. It is also used as an alloying agent used in the production of aluminum, beryllium, copper, lead, and magnesium alloys. Calcium is used as a reducing agent in the extraction of other metals, such as uranium, zirconium, and thorium. Calcium carbonate is used in manufacturing cement and mortar, lime and limestone. Used by many forms of life to make shells and bones. Virtually no use for the pure metal, however two of its compounds are, lime (CaO) and gypsum (CaSO4), are in great demand by a number of industries.

Sources

Obtained from minerals like chalk, limestone & marble. Pure metal is produced by replacing the calcium in lime (calcium carbonate, CaCO3) with aluminium in hot, low pressure retorts.

Abundance
Abundance in Earth's crust
41,500 mg/kg
Abundance in Oceans
412 mg/L
Abundance in Human Body
1.4 %
Abundance in Meteor
1.1 %
Abundance in Sun
0.007 %
Abundance in Universe
0.007 %

Nuclear Screening Constants

1s0.527
2p3.9586
2s6.2236
3p11.3417
3s10.3985
4s15.602