Ca - Calcium

20
Ca
Calcium

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

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*. You can also download Printable Periodic Table of Elements Flashcards for Calcium in a PDF format.

Calcium Facts

Read key information and facts about element Calcium

NameCalcium
Atomic Number20
Atomic SymbolCa
Atomic Weight40.078
PhaseSolid
ColorSilver
Appearance-
ClassificationAlkaline Earth Metal
Natural OccurancePrimordial
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
269
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'.

Discovered By H. Davy
Discovery Date 1808 in United Kingdom
First Isolation 1808
Isolated by H. Davy

Davy discovered the metal by electrolysis of quicklime.

Calcium Uses

Calcium is used to prepare thorium and uranium as reducing agents. It is also used as an alloying agent in aluminum, copper, lead, and magnesium.

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
Space Group Number225
Crystal StructureFace Centered Cubic
Number of atoms per unit cell4
20 Ca Calcium - Crystal Structure | SchoolMyKids

The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.

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 Calculated194 pm(1.94 Å)
Atomic Radius Empirical180 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

Spectral Lines of Calcium - Atomic Spectrum of Calcium

A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules.

Spectral lines are the result of interaction between a quantum system and a single photon. A spectral line may be observed either as an emission line or an absorption line.

Spectral lines are highly atom-specific, and can be used to identify the chemical composition of any medium. Several elements, including helium, thallium, and caesium, were discovered by spectroscopic means. They are widely used to determine the physical conditions of stars and other celestial bodies that cannot be analyzed by other means.

Emission spectrum of Calcium

Emission Spectrum of Calcium | SchoolMyKids

Absorption spectrum of Calcium

Absorption 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

Ionization energy is the amount of energy required to remove an electron from an atom or molecule.in chemistry, this energy is expresed in kilocalories per mole (kcal/mol) or kilojoules per mole (kJ/mol).

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

Electrical resistivity measures element's electrical resistance or how strongly it resists electric current.The SI unit of electrical resistivity is the ohm-metre (Ω⋅m). While Electrical conductivity is the reciprocal of electrical resistivity. It represents a element's ability to conduct electric current. The SI unit of electrical conductivity is siemens per metre (S/m).

Calcium is a conductor of electricity. Refer to table below for the Electrical properties of Calcium

Electrical conductors Conductor
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, 1547.330 °F)
Boiling Point1757 K(1483.85 °C, 2702.930 °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

Regulatory and Health - Health and Safety Parameters and Guidelines

The United States Department of Transportation (DOT) identifies hazard class of all dangerous elements/goods/commodities either by its class (or division) number or name. The DOT has divided these materials into nine different categories, known as Hazard Classes.

Substances liable to spontaneous combustion

NFPA 704 is a Standard System for the Identification of the Hazards of Materials for Emergency Response. NFPA is a standard maintained by the US based National Fire Protection Association.

The health (blue), flammability (red), and reactivity (yellow) rating all use a numbering scale ranging from 0 to 4. A value of zero means that the element poses no hazard; a rating of four indicates extreme danger.

NFPA Fire Rating1Flash Points Above 93.3°C (200°F)
NFPA Health Rating3 Flash Points below 37.8°C (100°F)
NFPA Reactivity Rating2 Flash Points Above 37.8°C (100°F) not exceeding 93.3°C (200°F)
NFPA HazardsWWater Reactive
Autoignition Point-
Flashpoint-

Database Search

List of unique identifiers to search the element in various chemical registry databases

DatabaseIdentifier number
CAS Number - Chemical Abstracts Service (CAS)CAS7440-70-2
RTECS Number-
CID Number CID5460341
Gmelin Number-
NSC Number-

Frequently Asked Questions (FAQ)

Find the answers to the most frequently asked questions about Calcium

The electronic configuration of Calcium is 1s2 2s2 2p6 3s2 3p6 4s2.

The abbreviated electronic configuration of Calcium is [Ar] 4s2. To form abbreviated notation of electronic configuration, the completely filled subshells are replaced by the noble gas of the preceding period in square brackets.

Symbol of Calcium is Ca. Calcium is a chemical element with symbol Ca and atomic number 20.

Calcium is a chemical element with the symbol Ca and atomic number 20. Calcium is the 20 element on the periodic table. It is located in group 2 and period 4 in the modern periodic table.

The atomic number of Calcium is 20.

Calcium is of Silver color.

The element Calcium was discovered by H. Davy in year 1808 in United Kingdom. Calcium was first isolated by H. Davy in 1808.

Calcium has 2 valence electrons. Calcium has 20 electrons out of which 2 valence electrons are present in the 4s2 outer orbitals of atom.

Melting Point of Calcium is 1115 K.

Boiling Point of Calcium is 1757 K.

Melting Point of Calcium in Kelvin is 1115 K.

Boiling Point of Calcium in Kelvin is 1757 K.

Melting Point of Calcium in Celsius is 841.85 °C.

Boiling Point of Calcium in Celsius is 1483.85 °C.

Melting Point of Calcium in Fahrenheit is 1547.33 °F.

Boiling Point of Calcium in Fahrenheit is 2702.93 °F.

The electronic configuration of Calcium will be 1s2 2s2 2p6 3s2 3p6 4s2.

The electronic configuration of Calcium will be 1s2 2s2 2p6 3s2 3p6 4s2.