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Ca Calcium
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

20
Ca
Calcium
Element 20 of Periodic table is Calcium with atomic number 20, atomic weight 40.078. Calcium, symbol Ca, has a Face Centered Cubic structure and Silver color. Calcium is a Alkaline Earth Metal element. It is part of group 2 (beryllium family). Know everything about Calcium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
20 Ca - Calcium | SchoolMyKids

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 Ca2+ is also the fifth-most-abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate.

It belongs to group 2 of the periodic table having trivial name alkaline earth metals*.

Calcium Facts

Read key information and facts about element Calcium

NameCalcium
Atomic Number20
Atomic SymbolCa
Atomic Weight40.078
PhaseSolid
ColorSilver
Appearance-
ClassificationAlkaline Earth Metal
Group in Periodic Table2
Group Nameberyllium family
Period in Periodic Tableperiod 4
Block in Periodic Tables -block
Electronic Configuration[Ar] 4s2
Electronic Shell Structure (Electrons per shell)2, 8, 8, 2
Melting Point1115 K
Boiling Point1757 K
CAS NumberCAS7440-70-2
Neighborhood Elements
123456789101112131415161718
1
1
H
Hydrogen
1.008

Atomic #

Electronic Shell #

Symbol
Name
Atomic Weight
HGas
HgLiquid
CSolid
Metals
Metalloids
NonMetals
Alkali metals
Alkali earth metals
Lanthanoids
Transition metals
Post-transition metals
Other nonmetals
Halogens
Nobel gas
Actinoids
2
He
Helium
4.003
2
3
Li
Lithium
6.941
4
Be
Beryllium
9.012
5
B
Boron
10.811
6
C
Carbon
12.011
7
N
Nitrogen
14.007
8
O
Oxygen
15.999
9
F
Fluorine
18.998
10
Ne
Neon
20.180
3
11
Na
Sodium
22.990
12
Mg
Magnesium
24.305
13
Al
Aluminium
26.982
14
Si
Silicon
28.085
15
P
Phosphorus
30.974
16
S
Sulfur
32.065
17
Cl
Chlorine
35.453
18
Ar
Argon
39.948
4
19
K
Potassium
39.098
20
Ca
Calcium
40.078
21
Sc
Scandium
44.956
22
Ti
Titanium
47.867
23
V
Vanadium
50.941
24
Cr
Chromium
51.996
25
Mn
Manganese
54.938
26
Fe
Iron
55.845
27
Co
Cobalt
58.933
28
Ni
Nickel
58.693
29
Cu
Copper
63.546
30
Zn
Zinc
65.409
31
Ga
Gallium
69.723
32
Ge
Germanium
72.640
33
As
Arsenic
74.922
34
Se
Selenium
78.960
35
Br
Bromine
79.904
36
Kr
Krypton
83.798
5
37
Rb
Rubidium
85.468
38
Sr
Strontium
87.620
39
Y
Yttrium
88.906
40
Zr
Zirconium
91.224
41
Nb
Niobium
92.906
42
Mo
Molybdenum
95.940
43
Tc
Technetium
98
44
Ru
Ruthenium
101.070
45
Rh
Rhodium
102.906
46
Pd
Palladium
106.420
47
Ag
Silver
107.868
48
Cd
Cadmium
112.411
49
In
Indium
114.818
50
Sn
Tin
118.710
51
Sb
Antimony
121.760
52
Te
Tellurium
127.600
53
I
Iodine
126.904
54
Xe
Xenon
131.293
6
55
Cs
Cesium
132.905
56
Ba
Barium
137.327
57 - 71
La - Lu
Lanthanides
72
Hf
Hafnium
178.490
73
Ta
Tantalum
180.948
74
W
Tungsten
183.840
75
Re
Rhenium
186.207
76
Os
Osmium
190.230
77
Ir
Iridium
192.217
78
Pt
Platinum
195.078
79
Au
Gold
196.967
80
Hg
Mercury
200.590
81
Tl
Thallium
204.383
82
Pb
Lead
207.200
83
Bi
Bismuth
208.980
84
Po
Polonium
209
85
At
Astatine
210
86
Rn
Radon
222
7
87
Fr
Francium
223
88
Ra
Radium
226
89 - 103
Ac - Lr
Actinides
104
Rf
Rutherfordium
261
105
Db
Dubnium
262
106
Sg
Seaborgium
266
107
Bh
Bohrium
264
108
Hs
Hassium
277
109
Mt
Meitnerium
268
110
Ds
Darmstadtium
281
111
Rg
Roentgenium
272
112
Cn
Copernicium
285
113
Nh
Nihonium
284
114
Fl
Flerovium
289
115
Mc
Moscovium
288
116
Lv
Livermorium
292
117
Ts
Tennessine
294
118
Og
Oganesson
294
Lanthanides
57
La
Lanthanum
138.905
58
Ce
Cerium
140.116
59
Pr
Praseodymium
140.908
60
Nd
Neodymium
144.240
61
Pm
Promethium
145
62
Sm
Samarium
150.360
63
Eu
Europium
151.964
64
Gd
Gadolinium
157.250
65
Tb
Terbium
158.925
66
Dy
Dysprosium
162.500
67
Ho
Holmium
164.930
68
Er
Erbium
167.259
69
Tm
Thulium
168.934
70
Yb
Ytterbium
173.040
71
Lu
Lutetium
174.967
Actinides
89
Ac
Actinium
227
90
Th
Thorium
232.038
91
Pa
Protactinium
231.036
92
U
Uranium
238.029
93
Np
Neptunium
237
94
Pu
Plutonium
244
95
Am
Americium
243
96
Cm
Curium
247
97
Bk
Berkelium
247
98
Cf
Californium
251
99
Es
Einsteinium
252
100
Fm
Fermium
257
101
Md
Mendelevium
258
102
No
Nobelium
259
103
Lr
Lawrencium
262

How to Locate Calcium on Periodic Table

Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 20 to find Calcium on periodic table.

Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Calcium on periodic table look for cross section of group 2 and period 4 in the modern periodic table.

Calcium History

The element Calcium was discovered by H. Davy in year 1808 in United Kingdom. Calcium was first isolated by H. Davy in 1808. Calcium derived its name from the Latin calx, meaning 'lime'.

Davy discovered the metal by electrolysis of quicklime.

Calcium Presence: Abundance in Nature and Around Us

The table below shows the abundance of Calcium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.

 ppb by weight (1ppb =10^-7 %)ppb by atoms (1ppb =10^-7 %)
Abundance in Universe700002000
Abundance in Sun700002000
Abundance in Meteorites110000005200000
Abundance in Earth's Crust5000000026000000
Abundance in Oceans4220650
Abundance in Humans140000002200000

Crystal Structure of Calcium

The solid state structure of Calcium is Face Centered Cubic.

The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.

Unit Cell Parameters

The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)

abc
558.84 pm558.84 pm558.84 pm

and the angles between them Lattice Angles (alpha, beta and gamma).

alphabetagamma
π/2 π/2 π/2

The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.

The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.

Space Group NameFm_ 3m 20 Ca Calcium - Crystal Structure | SchoolMyKids
Oxidation StatesSpace Group Number225
Crystal StructureFace Centered Cubic

Calcium Atomic and Orbital Properties

Calcium atoms have 20 electrons and the electronic shell structure is [2, 8, 8, 2] with Atomic Term Symbol (Quantum Numbers) 1S0.

Atomic Number20
Number of Electrons (with no charge)20
Number of Protons20
Mass Number40
Number of Neutrons20
Shell structure (Electrons per energy level)2, 8, 8, 2
Electron Configuration[Ar] 4s2
Valence Electrons4s2
Valence (Valency)2
Main Oxidation States2
Oxidation States1, 2
Atomic Term Symbol (Quantum Numbers)1S0

Bohr Atomic Model of Calcium - Electrons per energy level

20 Ca Calcium - Electron Shell Structure | SchoolMyKids
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Ground State Electronic Configuration of Calcium - neutral Calcium atom

Abbreviated electronic configuration of Calcium

The ground state abbreviated electronic configuration of Neutral Calcium atom is [Ar] 4s2. The portion of Calcium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Ar]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 4s2, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Calcium

Complete ground state electronic configuration for the Calcium atom, Unabbreviated electronic configuration

1s2 2s2 2p6 3s2 3p6 4s2

Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.

  • As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
  • The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
  • Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
  • Electron configuration of Calcium
    Atomic Structure of Calcium

    Calcium atomic radius is 194 pm, while it's covalent radius is 174 pm.

    Atomic Radius Calculated

    194 pm (1.94 Å)

    Atomic Radius Empirical

    180 pm (1.8 Å)

    Atomic Volume25.857 cm3/mol
    Covalent Radius174 pm (1.74 Å)
    Van der Waals Radius231 pm
    Neutron Cross Section0.43
    Neutron Mass Absorption 0.00037

    Atomic Spectrum of Calcium

    Atomic Spectrum of Calcium | SchoolMyKids

    Calcium Chemical Properties: Calcium Ionization Energies and electron affinity

    The electron affinity of Calcium is 2.37 kJ/mol.

    Valence2
    Electronegativity1
    ElectronAffinity2.37 kJ/mol

    Ionization Energy of Calcium

    Refer to table below for Ionization energies of Calcium

    Ionization energy numberEnthalpy - kJ/mol
    1st589.8
    2nd1145.4
    3rd4912.4
    4th6491
    5th8153
    6th10496
    7th12270
    8th14206
    9th18191
    10th20385
    11th57110
    12th63410
    13th70110
    14th78890
    15th86310
    16th94000
    17th104900
    18th111711
    19th494850
    20th527762

    Calcium Physical Properties

    Refer to below table for Calcium Physical Properties

    Density1.55 g/cm3(when liquid at m.p density is $1.378 g/cm3)
    Molar Volume25.857 cm3/mol

    Elastic Properties

    Young Modulus20
    Shear Modulus7.4 GPa
    Bulk Modulus 17 GPa
    Poisson Ratio0.31

    Hardness of Calcium - Tests to Measure of Hardness of Element

    Mohs Hardness1.75 MPa
    Vickers Hardness-
    Brinell Hardness167 MPa

    Calcium Electrical Properties

    Calcium is Conductor of electricity. Refer to table below for the Electrical properties ofCalcium

    Electrical Conductivity29000000 S/m
    Resistivity3.4e-8 m Ω
    Superconducting Point-

    Calcium Heat and Conduction Properties

    Thermal Conductivity200 W/(m K)
    Thermal Expansion0.0000223 /K

    Calcium Magnetic Properties

    Magnetic TypeParamagnetic
    Curie Point-
    Mass Magnetic Susceptibility1.38e-8 m3/kg
    Molar Magnetic Susceptibility5.531e-10 m3/mol
    Volume Magnetic Susceptibility0.00002139

    Optical Properties of Calcium

    Refractive Index-

    Acoustic Properties of Calcium

    Speed of Sound3810 m/s

    Calcium Thermal Properties - Enthalpies and thermodynamics

    Refer to table below for Thermal properties of Calcium

    Melting Point1115 K (841.85°C, 1547.3300000000002 °F)
    Boiling Point1757 K (1483.85°C, 2702.93 °F)
    Critical Temperature-
    Superconducting Point-

    Enthalpies of Calcium

    Heat of Fusion8.54 kJ/mol
    Heat of Vaporization155 kJ/mol
    Heat of Combustion-990 J/(kg K)

    Calcium Isotopes - Nuclear Properties of Calcium

    Calcium has 24 isotopes, with between 34 and 57 nucleons. Calcium has 5 stable naturally occuring isotopes.

    Isotopes of Calcium - Naturally occurring stable Isotopes: 40Ca, 42Ca, 43Ca, 44Ca, 46Ca.

    IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
    34Ca201434Synthetic
    35Ca201535Synthetic
    36Ca201636Synthetic
    37Ca201737Synthetic
    38Ca201838Synthetic
    39Ca201939Synthetic
    40Ca20204096.941%Stable
    41Ca202141Synthetic
    42Ca2022420.647%StableN/A
    43Ca2023430.135%StableN/A
    44Ca2024442.086%StableN/A
    45Ca202545Synthetic
    46Ca2026460.004%StableN/A
    47Ca202747Synthetic
    48Ca2028480.187%StableN/A
    49Ca202949Synthetic
    50Ca203050Synthetic
    51Ca203151Synthetic
    52Ca203252Synthetic
    53Ca203353Synthetic
    54Ca203454Synthetic
    55Ca203555Synthetic
    56Ca203656Synthetic
    57Ca203757Synthetic