Ba - Barium

56
Ba
Barium

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

Element 56 of Periodic table is Barium with atomic number 56, atomic weight 137.327. Barium, symbol Ba, has a Body Centered Cubic structure and Silver color. Barium is a Alkaline Earth Metal element. It is part of group 2 (beryllium family). Know everything about Barium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
56 Ba - Barium | SchoolMyKids

Barium is a chemical element with symbol Ba and atomic number 56. It is the fifth element in Group 2, a soft silvery metallic Alkaline Earth Metal. Because of its high chemical reactivity barium is never found in nature as a free element.

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 Barium in a PDF format.

Barium Facts

Read key information and facts about element Barium

NameBarium
Atomic Number56
Atomic SymbolBa
Atomic Weight137.327
PhaseSolid
ColorSilver
Appearance-
ClassificationAlkaline Earth Metal
Natural OccurancePrimordial
Group in Periodic Table2
Group Nameberyllium family
Period in Periodic Tableperiod 6
Block in Periodic Tables-block
Electronic Configuration[Xe] 6s2
Electronic Shell Structure (Electrons per shell)2, 8, 18, 18, 8, 2
Melting Point1000 K
Boiling Point2143 K
CAS NumberCAS7440-39-3
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 Barium 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 56 to find Barium 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 Barium on periodic table look for cross section of group 2 and period 6 in the modern periodic table.

Barium History

The element Barium was discovered by W. Scheele in year 1772 in United Kingdom. Barium was first isolated by H. Davy in 1808. Barium derived its name from the Greek barys, meaning 'heavy'.

Discovered By W. Scheele
Discovery Date 1772 in United Kingdom
First Isolation 1808
Isolated by H. Davy

Scheele distinguished a new earth (BaO) in pyrolusite and Davy isolated the metal byelectrolysis.

Barium Uses

Barium is used to create a green glow in pyrotechnics. It is also used to remove gases from vacuum tubes. Compounds of barium are used as a contrast medium in X-rays.

Barium Presence: Abundance in Nature and Around Us

The table below shows the abundance of Barium 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 Universe100.09
Abundance in Sun100.1
Abundance in Meteorites2800410
Abundance in Earth's Crust34000051000
Abundance in Oceans301.4
Abundance in Humans30014

Crystal Structure of Barium

The solid state structure of Barium is Body 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
502.8 pm502.8 pm502.8 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 NameIm_ 3m
Space Group Number229
Crystal StructureBody Centered Cubic
Number of atoms per unit cell2
56 Ba Barium - 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.

Barium Atomic and Orbital Properties

Barium atoms have 56 electrons and the electronic shell structure is [2, 8, 18, 18, 8, 2] with Atomic Term Symbol (Quantum Numbers) 1S0.

Atomic Number56
Number of Electrons (with no charge)56
Number of Protons56
Mass Number137
Number of Neutrons81
Shell structure (Electrons per energy level)2, 8, 18, 18, 8, 2
Electron Configuration[Xe] 6s2
Valence Electrons6s2
Valence (Valency)2
Main Oxidation States2
Oxidation States1, 2
Atomic Term Symbol (Quantum Numbers)1S0

Bohr Atomic Model of Barium - Electrons per energy level

56 Ba Barium Electron Shell Structure | SchoolMyKids
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Ground State Electronic Configuration of Barium - neutral Barium atom

Abbreviated electronic configuration of Barium

The ground state abbreviated electronic configuration of Neutral Barium atom is [Xe] 6s2. The portion of Barium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Xe]. 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 6s2, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Barium

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

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 6s2

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 Barium

Atomic Structure of Barium

Barium atomic radius is 253 pm, while it's covalent radius is 198 pm.

Atomic Radius Calculated253 pm(2.53 Å)
Atomic Radius Empirical215 pm (2.15 Å)
Atomic Volume38.16 cm3/mol
Covalent Radius198 pm (1.98 Å)
Van der Waals Radius268 pm
Neutron Cross Section1.3
Neutron Mass Absorption 0.00027

Spectral Lines of Barium - Atomic Spectrum of Barium

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 Barium

Emission Spectrum of Barium | SchoolMyKids

Absorption spectrum of Barium

Absorption Spectrum of Barium | SchoolMyKids

Barium Chemical Properties: Barium Ionization Energies and electron affinity

The electron affinity of Barium is 13.95 kJ/mol.

Valence2
Electronegativity0.89
ElectronAffinity13.95 kJ/mol

Ionization Energy of Barium

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 Barium

Ionization energy numberEnthalpy - kJ/mol
1st502.9
2nd965.2
3rd3600

Barium Physical Properties

Refer to below table for Barium Physical Properties

Density3.51 g/cm3(when liquid at m.p density is $3.338 g/cm3)
Molar Volume38.16 cm3/mol

Elastic Properties

Young Modulus13
Shear Modulus4.9 GPa
Bulk Modulus 9.6 GPa
Poisson Ratio-

Hardness of Barium - Tests to Measure of Hardness of Element

Mohs Hardness1.25 MPa
Vickers Hardness-
Brinell Hardness-

Barium 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).

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

Electrical conductors Conductor
Electrical Conductivity2900000 S/m
Resistivity3.5e-7 m Ω
Superconducting Point-

Barium Heat and Conduction Properties

Thermal Conductivity18 W/(m K)
Thermal Expansion0.0000206 /K

Barium Magnetic Properties

Magnetic TypeParamagnetic
Curie Point-
Mass Magnetic Susceptibility1.13e-8 m3/kg
Molar Magnetic Susceptibility1.552e-9 m3/mol
Volume Magnetic Susceptibility0.00003966

Optical Properties of Barium

Refractive Index-

Acoustic Properties of Barium

Speed of Sound1620 m/s

Barium Thermal Properties - Enthalpies and thermodynamics

Refer to table below for Thermal properties of Barium

Melting Point1000 K(726.85 °C, 1340.330 °F)
Boiling Point2143 K(1869.85 °C, 3397.730 °F)
Critical Temperature-
Superconducting Point-

Enthalpies of Barium

Heat of Fusion8 kJ/mol
Heat of Vaporization140 kJ/mol
Heat of Combustion-

Barium Isotopes - Nuclear Properties of Barium

Barium has 40 isotopes, with between 114 and 153 nucleons. Barium has 7 stable naturally occuring isotopes.

Isotopes of Barium - Naturally occurring stable Isotopes: 130Ba, 132Ba, 134Ba, 135Ba, 136Ba, 137Ba, 138Ba.

IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
114Ba5658114Synthetic
115Ba5659115Synthetic
116Ba5660116Synthetic
117Ba5661117Synthetic
118Ba5662118Synthetic
119Ba5663119Synthetic
120Ba5664120Synthetic
121Ba5665121Synthetic
122Ba5666122Synthetic
123Ba5667123Synthetic
124Ba5668124Synthetic
125Ba5669125Synthetic
126Ba5670126Synthetic
127Ba5671127Synthetic
128Ba5672128Synthetic
129Ba5673129Synthetic
130Ba56741300.106%StableN/A
131Ba5675131Synthetic
132Ba56761320.101%StableN/A
133Ba5677133Synthetic
134Ba56781342.417%StableN/A
135Ba56791356.592%StableN/A
136Ba56801367.854%StableN/A
137Ba568113711.232%Stable
138Ba568213871.698%StableN/A
139Ba5683139Synthetic
140Ba5684140Synthetic
141Ba5685141Synthetic
142Ba5686142Synthetic
143Ba5687143Synthetic
144Ba5688144Synthetic
145Ba5689145Synthetic
146Ba5690146Synthetic
147Ba5691147Synthetic
148Ba5692148Synthetic
149Ba5693149Synthetic
150Ba5694150Synthetic
151Ba5695151Synthetic
152Ba5696152Synthetic
153Ba5697153Synthetic

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 which in contact with water emit flammable gases

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 Rating2 Flash Points Above 37.8°C (100°F) not exceeding 93.3°C (200°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)CAS7440-39-3
RTECS NumberRTECSCQ8370000
CID Number CID5355457
Gmelin Number-
NSC Number-

Frequently Asked Questions (FAQ)

Find the answers to the most frequently asked questions about Barium

The electronic configuration of Barium is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 6s2.

The abbreviated electronic configuration of Barium is [Xe] 6s2. 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 Barium is Ba. Barium is a chemical element with symbol Ba and atomic number 56.

Barium is a chemical element with the symbol Ba and atomic number 56. Barium is the 56 element on the periodic table. It is located in group 2 and period 6 in the modern periodic table.

The atomic number of Barium is 56.

Barium is of Silver color.

The element Barium was discovered by W. Scheele in year 1772 in United Kingdom. Barium was first isolated by H. Davy in 1808.

Barium has 2 valence electrons. Barium has 56 electrons out of which 2 valence electrons are present in the 6s2 outer orbitals of atom.

Melting Point of Barium is 1000 K.

Boiling Point of Barium is 2143 K.

Melting Point of Barium in Kelvin is 1000 K.

Boiling Point of Barium in Kelvin is 2143 K.

Melting Point of Barium in Celsius is 726.85 °C.

Boiling Point of Barium in Celsius is 1869.85 °C.

Melting Point of Barium in Fahrenheit is 1340.33 °F.

Boiling Point of Barium in Fahrenheit is 3397.73 °F.

The electronic configuration of Barium will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 6s2.

The electronic configuration of Barium will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 6s2.